DBS Control Record -
General Fields:
1. Version - This field is the version number of
the DBS Control
Record. It is incremented by 1 when it
becomes necessary to
migrate the DBS Control Record to a new
format. This field
cannot be modified by the DBSControl
utility program.
Recommended setting:
==> Cannot be modified
2. SysInit - Upon successful completion, the
SYSINIT utility program
will set this field to TRUE. The default
value is FALSE.
When SysInit flag is TRUE, sysinit time
(yyyy-mm-dd hh:mi)
is displayed if available. This field
cannot be modified by
the DBSControl utility program.
Recommended setting:
==> Cannot be modified
3. DeadLockTimeout - This field is used by the
Dispatcher to
determine the interval, in seconds, between
deadlock time-
out detection cycles. The default value is 240.
Default: ==> 240
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> YES
4. (Reserved for future use)
5. HashFuncDBC - This field defines the hashing
function that will
be used by the DBS. The default value is 6
(MSCHASH_P90_UNI_5R).
This field cannot be modified by the
DBSControl utility program.
Recommended setting:
==> Cannot be modified
6. (Reserved for future use)
7. (Reserved for future use)
8. SessionMode - This field defines the system
default transaction
mode, case sensitivity, and character
truncation rule for a session.
The setting is either 0 (Teradata) or 1
(ANSI). The default is Teradata.
The ANSI setting defaults SQL sessions
to ANSI transaction semantics,
case sensitive data, and error reporting on
truncation of character
data. The Teradata setting defaults SQL
sessions to Teradata
transaction semantics, case insensitive
data, and no error reporting
on truncation of character data.
Default: ==> 0
(Teradata)
Recommended setting:
==> Customer preference
Tpareset Required?
==> YES
9. LockLogger - This Field defines the system
default for the
locking logger. This allows the DBA to log
the delays caused by
database locks to help in identifying lock
conflicts. To enable
this feature set the field to TRUE. To
disable the feature set the
field to FALSE.
Default: ==> FALSE
Recommended setting:
==> FALSE (see Reference Article)
Tpareset Required?
==> YES
10.
RollbackPriority - This Field defines the system default for the
rollback priority. This allows the DBA to
either take the default
priority of Rush or the user's logon
priority. To enable this feature
set the field to TRUE. To disable the
feature set the field to FALSE.
Note that this new feature will affect all
users on the system.
Default: ==> FALSE
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> YES
11.
MaxLoadTasks - Maximum combined number of FastLoad, MultiLoad,
and possibly FastExport. This field works
differently depending on
the value of MaxLoadAWT.
a) If the field MaxLoadAWT is zero (by
default), this field is
the concurrent job limit for all three
utilities: FastLoad, MultiLoad,
and FastExport.
b) If the field MaxLoadAWT is changed to
non-zero, this field is
the concurrent job limit for only two
utilities: FastLoad and
MultiLoad.
The valid range is 0 .. 30. The default is 5.
NOTE: This field can only be set to greater
than 15 if the field
MaxLoadAWT is changed from the
default of zero.
Default: ==> 5
Recommended setting:
==> Customer tunable (see Reference Article)
Tpareset Required?
==> NO
12.
RollForwardLock - This field defines the system default for the
RollForward Using Row Hash Locks
option. This allows the DBA to
specify that row hash locks should be used
to lock the target
table rows during a RollForward. To enable this feature set the
field to TRUE. To disable the feature set the field to
FALSE.
Note that this new feature will affect all
users on the system.
Default: ==> FALSE
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> YES
13.
MaxDecimal - Maximum number of Decimal Digits in the default
max value used in expression typing. 0 is
system default, because
of initialization of SysDBSControl, and
means use 15. Other valid
values are presently 15, 18, and 38 .
Default: ==> 15
Recommended setting:
==> Customer tunable (see Reference Article)
Tpareset Required?
==> YES
14.
CenturyBreak - This field defines which Teradata Dates are
specific to the 21st Century. For example, C = 25, strings
inserted such as 00/01/01 and 24/01/01 will
assume the years
2000 and 2024 respectively. A string inserted as 25/01/01
will assume the year 1925. Valid values range from 0 to 100.
Default: ==> 0 (15)
Reference Article:
==> N/A
Recommended setting:
==> Customer tunable (see Reference Article)
Tpareset Required?
==> NO
15.
DateForm - This field defines whether IntegerDate (0)
or ANSIDate (1) is used for a session.
Default: ==> (0)
IntegerDate
Recommended setting:
==> Customer preference (see Reference Article)
Tpareset Required?
==> No
16.
System Time Zone Hour - This field defines the System TimeZone
Hour offset from UTC. Permitted range: -12 to 14.
Default: ==> 0
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
17.
System Time Zone Minute - This field defines the System Time Zone
Minute offset from UTC. Permitted range: -59 to 59.
Default: ==> 0
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required? ==>
NO
18.
System Time Zone String - This field displays the System TimeZone String.
It is set up using the tdlocaledef utility
and any changes
will have to be done through the same.
Default: ==> 0
Recommended setting:
==> Customer tunable (see Reference Articles)
Tpareset Required?
==> NO
19.
(Reserved for future use)
20.
RoundHalfwayMagUp - This field indicates how rounding should
be performed when computing values of
DECIMAL type. If this
field is FALSE, the system uses the
rounding semantics
traditional for Teradata, namely, a value
exactly halfway
between representable decimal values is
rounded up or down
so that the least significant digit is
even. If TRUE, the
system uses rounding semantics appropriate
for many business
applications, namely, the magnitude of
halfway values are
rounded up.
Put differently, halfway values are rounded
away from zero, so that positive halfway
values are rounded
up and negative halfway values are rounded
down (toward
negative infinity).
Default: ==> FALSE
Recommended setting:
==> Customer preference (see Reference Article)
Tpareset Required?
==> YES
21.
(Reserved for future use)
22.
Target Level Emulation - Used when a user wants to emulate a Target
Machine.
TRUE means the user wants to run Target
Level Emulation.
FALSE means the user does not. The default is FALSE.
Default: ==> FALSE
Recommended setting:
==> FALSE (see Reference Article)
Tpareset Required?
==> NO
23.
Export Width Table ID - The Export Width Table ID.
This is the Export length adjustment
required for inclusion
of SO and SI characters. 'Expected Defaults' is an expected
width adjustment of 2. 'Compatability Defaults' is an expected
width adjustment of 0 and 'Maximum
Defaults' is a expected
width adjustment of 1.
For Expected Defaults, enter : 0
For Compatibility Defaults, enter : 1
For Maximum Defaults, enter : 2
Default: ==> 0
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> YES
24.
DBQL Log Last Resp - This field indicates whether DBQL
should generate a pseudo RESP step for each
request that is logged
to the DBC.DBQLogTbl (not requests logged
to DBQLSummaryTbl).
The pseudo RESP step is logged to the
DBQLStepTbl after the last
response is sent to the client/host and the
request is complete.
This allows an administrator to know the
actual response time
seen by the client/host.
TRUE means the user wants the RESP step
logged.
FALSE means the user does not. The default is FALSE.
Default:
==> FALSE
Recommended setting:
==> Customer preference (see Reference Article)
Tpareset Required?
==> NO
25.
DBQL Options - indicates special options of DBQL,
add values together to set applicable bit
flags
0: No special options
1: Long QueryId: No longer used, value does
not matter and flag
will not be reused for another purpose.
TD12.0 and later
always use a large queryid.
2: DBQL_QS_OPT: Enable diagnostics for
timestamp and
summary queryseconds issues
bit2 on:
DBQL_QS diagnostics enabled
bit2 off: DBQL_QS diagnostics disabled
Change to DBQL_QS_OPT bit2 is effective
after write.
Default:
==> 0
Reference Article:
==> N/A
Recommended setting:
==> Default (This field is obsolete as of TD12)
Tpareset Required?
==> N/A
26.
ExternalAuthentication - This field indicates whether external
authentication is enabled. The valid values
are 0, 1 and 2.
0: Accept both external authentication and
traditional logons.
1: Reject external authentication and
accept traditional logons.
2: Accept external authentication and
reject traditional logons.
The default value is 0.
Default:
==> 0 (ON)
Recommended setting:
==> Customer tunable
Tpareset Required?
==> NO
27.
IdCol Batch Size - Indicates the size of the pool of
numbers to be reserved for generating
numbers for a
batch of rows to be bulk-inserted into a
table with
an identity column. The valid range of
value is
1 .. 1000000. The default value is 100000.
Default: ==> 100000
Recommended setting:
==> Default (Customer tunable, see Reference Article)
Tpareset Required?
==> NO
28.
LockLogger Delay Filter - Indicate whether locking
logger delay filter is ON. If it is ON, the
delay filter
time in field 29 will take effect. The
default is OFF.
Default: ==> FALSE
(OFF)
Recommended setting:
==> FALSE (Enable as needed, see Reference Article)
Tpareset Required?
==> NO
29.
LockLogger Delay Filter Time - Indicates the delay filter
time used by locking logger. Only blocked
lock request with
delay time greater than this value will be
logger. The valid
range is 0 .. 1000000 seconds, default is 0
second.
Default:
==> 0 (seconds)
Recommended setting:
==> 1 to 10 seconds when enabled (see Reference Article)
Tpareset Required?
==> No
30.
ObjectUseCountCollectRate - Specifies the amount of time in minutes
after which the system updates
DBC.ObjectUsage with collected use
count information. While the specified time
guarantees a flush at the
given interval, a flush can still occur if
the object use count cache
is full. The minimum value is 1 minute and
the maximum value is 32767
minutes. The default value is 10 minutes.
The minimum recommended value
is 10 minutes.
Default:
==> 10 minutes.
Recommended setting:
==> 10 minutes.
Tpareset Required?
==> NO
31.
LockLogSegmentSize - Indicates the size of the
locking logger segment used by the lock
manager in kilo bytes.
The minimum value is 64 KB and maximum
value is 1024 KB.
Default:
==> 64KB
Recommended setting:
==> 64KB (see Reference Article)
Tpareset Required?
==> YES
32.
CostProfileId - This value is used to select
the cost profile from DBC.CostProfiles that
will be used to
create cost prediction method parameter
values. The profile
with DBC.CostProfiles.ProfileId ==
CostProfileId will be chosen.
If CostProfileId doesn't match any
ProfileId value, then the
system default profile
(DBC.CostProfiles.ProfileId == 0) is used.
If the system default profile cannot be
read then the bootstrap
profile is used.
Default:
==> 0
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> NO
33.
DBQLFlushRate - Determines the frequency for writing DBQL
cache entries to DBQL dictionary
tables. Default is 600
seconds (10 minutes). Valid range is 1 to 3600 seconds.
The recommended value is 600 seconds or
more.
Default:
==> 600 seconds
Recommended setting:
==> 600 seconds or more
Tpareset Required?
==> NO
34.
Memory Limit Per Transaction - Specifies the maximum amount
(number of pages) of in-memory temporary
storage that can be used
by the RSG to store the records for one
transaction.
If the transaction exhausts this amount,
then it is moved to
a disk file (specified by general field
number 37).
The default value is 2 pages. The minimum value
is 0 page
and maximum value is 127 pages.
Default:
==> 2 pages
Recommended setting:
==> Default (Customer tunable, see Reference Article)
Tpareset Required? ==> YES
35.
Client Reset Timeout - Specifies how long the RSG should wait
for an intermediary to reconnect after a
communication failure,
an intermediary reset, or a server reset
before taking the
needed actions. The default value is 300 seconds.
The minimum value is 0 sec and maximum
value is 65535 sec.
Default:
==> 300 seconds
Recommended setting:
==> Default (Customer tunable, see Reference Article)
Tpareset Required?
==> YES
36.
Temporary Storage Page Size - Specifies the size (in KB) of a memory
page that is used to store data rows of a
replicated
transaction. The default value is 4 KB.
The minimum value is 1 KB and maximum value
is 1024 KB.
Default:
==> 4KB
Recommended setting:
==> Default (Customer tunable, see Reference Article)
Tpareset Required?
==> YES
37.
Spill File Path - Specifies a directory that will be used
by the RSG for spill files.
The default path is
/var/opt/teradata/tdtemp/tdrsg.
Default: ==> Linux =
/var/opt/teradata/tdtemp/tdrsg
Recommended setting:
==> Default (Customer preference, any valid path)
Tpareset Required?
==> YES
38.
MDS Is Enabled - Assumed that the MDS
packages are installed,
the MDS will be running if this flag is
TRUE. The default is FALSE.
Default: ==> FALSE
Recommended setting:
==> Customer preference (see Reference Article)
Tpareset Required?
==> YES
39.
ChecktableTableLockRetryLimit (Default = 0 is retry forever).
When a table is locked, checktable will
retry until it gets the table.
If the retry limit is set, checktable will retry
within the specified
limit.
Retry limit range = 0 to 32767 minutes
Default: ==> 0
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> NO
40.
EnableCostProfileTLE - This boolean determines whether new Optimizer
Cost Profile System (OCES) diagnostics are
enabled in combination with
Target Level Emulation (TLE). This is
initialized to FALSE. Attempts to
use combined OCES and TLE diagnostic syntax
will get a syntax error.
When set to TRUE, combined OCES/TLE
diagnostic syntax is enabled. When
enabled all TLE diagnostics are also
processed by the new OCES logic.
If EnableSetCostProfile == 0, then this
field will be set FALSE.
Default: ==> FALSE
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> NO
41.
EnableSetCostProfile - This controls usage of DIAGNOSTIC SET PROFILE...
statements to dynamically change cost
profiles used for query planning.
Meaningful values are 0, 1, and 2. If this == 0, then the statements
are disabled and will produce syntax error
messages. If this == 1, then
profiles can be activated only at SESSION
or REQUEST level. If this == 2
then profiles can be activated at any
level. The default value is 0, and
the legal range is 0..2.
Default: ==> 0
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> NO
42.
(Reserved for future use)
43.
DisableUDTImplCastForSysFuncOp - This field disables/enables
implicit cast/conversion of UDT expressions
passed to system
operators/functions. Conversions are from
UDTs to compatible
predefined types. A value of TRUE disables
implicit conversions.
A value of FALSE enables. The default is
FALSE.
Default: ==> FALSE
Recommended setting:
==> Default (Customer preference)
Tpareset Required?
==> NO
44.
CurHashBucketSize - This field defines the number of
bits currently used for the hash bucket
size.
The valid values are 16 or 20, which
correspond to the
number of hash buckets in the system as
follows:
16: The system is configured for 16-bit
hash buckets.
The system has 2^16 = 65,536 (64K) hash
buckets.
20: The system is configured for 20-bit
hash buckets.
The system has 2^20 = 1,048,576 (1M)
hash buckets.
The default value is 20.
Recommended setting:
==> This field is informational only.
45.
NewHashBucketSize - This field defines the number of
bits which will be used for the hash bucket
size in
the system after the next reconfig or
sysinit.
The valid values are 16 or 20, which
correspond to the
number of hash buckets in the system as
follows:
16: The system will use 16-bit hash
buckets.
The system will have 2^16 = 65,536
(64K) hash buckets.
20: The system will use 20-bit hash
buckets.
The system will have 2^20 = 1,048,576
(1M) hash buckets.
The default value is 20.
Default: ==> 20 for
new installations; 16 for upgrades from pre-TD12
Recommended setting:
==> 20
Tpareset Required?
==> Changes take effect after next sysinit or reconfig
46.
MaxLoadAWT - This field defines the maximum number of
AMP worker tasks (AWT) that concurrent
FastLoad and MultiLoad
can use altogether. The valid range is 0 ..
(60% of maxampworkertasks).
If the value is zero, this AWT limit check
is not performed.
The default is zero. This field can only be
set to zero if the
MaxLoadTasks is less than or equal to
15.
This field also affects the behavior of the
MaxLoadTasks field.
If it is zero (by default), the
MaxLoadTasks field is the concurrent
job limit for all three utilities:
FastLoad, MultiLoad, and FastExport.
If it is non-zero, the MaxLoadTasks field
is the concurrent job limit
for only two utilities: FastLoad and
MultiLoad.
Default: ==> 0
Recommended setting:
==> Customer tunable (see Reference Article)
Tpareset Required?
==> NO
47.
MaxRowHashBlocksPercent - This field defines the maximum percentage
of an AMP Lock Table's control blocks that
a transaction can utilize
for its rowhash locks. The transaction
would be aborted if its rowhash
locks exceed this threshold on any AMP. The
default value for
MaxRowHashBlocksPercent is 50. A value of 0
indicates that the system
will use the default value.
Default: ==> 50%
Recommended setting:
==> Customer tunable (see Reference Article)
Tpareset Required?
==> NO
48.
MonSesCPUNormalization - This field disables/enables
normalization of CPU values in Monitor
Session response.
A value of FALSE disables normalization of
CPU values.
A value of TRUE enables the normalization.
The default is FALSE.
Recommended procedure to change this flag
to avoid inconsistent TDWM
exception
behavior:
1) Disable TDWM Category 3 if enabled.
Adjust CPU related exception
thresholds.
2) Set Monitor Session Rate to zero.
3) Change MonSesCPUNormalization flag.
4) Set Monitor Session Rate to previous
non-zero value.
5) Enable TDWM Category 3 if it was
previously enabled.
Default: ==> FALSE
Recommended setting:
==> Default (Customer preference - see Reference Article)
Tpareset Required?
==> NO
49.
TempLargePageSize - This field specifies another method of RSG
storage memory pool in addition to the
existing temporary storage page
size. If a transaction contains any record
that exceeds the small page
size, then RSG will allocate memory from
the large page size. If that
is also not sufficient enough to hold a
transaction, then the entire
transaction is spilled to disk. The default
value for
TempLargePageSize is 64K Bytes. A value of
0 indicates that the system
will use the default value.
Default: ==> 64K
Recommended setting:
==> Default (Customer tunable - see Reference Article)
Tpareset Required? ==>
YES
50.
RepCacheSegSize - This field specifies the size of a cache segment
(in kilobytes) that is allocated in each
AMP to store EVLobjects,
which consist of executable code and
related metadata that is used
by the replication system to convert row
images into the external
format. The default value for
RepCacheSegSize is 512K Bytes. A value
of 0 indicates that the system will use the
default value.
Default: ==> 512KB
Recommended setting:
==> Default (Customer tunable - see Reference Article)
Tpareset Required?
==> YES
51.
MaxDownRegions - Sets the maximum allowable number of down regions for a
subtable.
The valid range is 0 to 12. When
this value is set to
zero, a subtable with fatal file system
error will be forced to mark down
on all the AMPs, if it is possible. Same action applies when this value is
exceeded.
Other than those the subtable will mark with down region.
The maximum value is 12 and the default
value is 6.
Default: ==> 6
Recommended setting: ==>
Default (Customer tunable - see Reference Article)
Tpareset Required?
==> YES
52.
MPS_IncludePEOnlyNodes - This flag is used to include PE-only nodes in
Monitor Physical Summary PM/API response
calculation.
The default is FALSE, i.e., PE-only nodes,
nodes configured with zero
AMPs, are excluded from Monitor Physical Summary
response calculation by
default.
Default: ==> FALSE
Recommended setting:
==> Default (Customer preference - see Reference Article)
Tpareset Required?
==> NO
53.
PrimaryIndexDefault - This field determines whether a primary index is
automatically created for tables whose
definitions do not explicitly
include the PRIMARY INDEX, NO PRIMARY
INDEX, PRIMARY KEY, or UNIQUE
clauses. When this value is set to P or D,
the first column of such
tables is automatically designated a nonunique
primary index (NUPI). When
this value is set to N, these tables are created
without primary indexes,
as NoPI tables.
Default: ==> D
Recommended setting:
==> Default (Customer preference - see Reference Article)
Tpareset Required?
==> NO
54.
AccessLockForUncomRead - This field, when enabled, imposes
access lock on source table(s) of DML
statement when
transaction isolation level is Read
Uncommitted (RU).
This flag only affects DMLs that involve
data modification.
The default value is FALSE.
Default: ==> FALSE
Recommended setting:
==> Default (Customer preference - see Reference Article)
Tpareset Required?
==> NO
55.
EnabNonTempoOp - This field is to enable
nontemporal operations such as NONTEMPORAL
DELETE,
NONTEMPORAL UPDATE, NONTEMPORAL INSERT, and
NONTEMPORAL ALTER TABLE. A nontemporal
operation is
a DML activity that either causes rows to
be deleted
or the TransactionTime column values to be
set
differently. To perform such operations,
the site
must first set the flag to TRUE and then
submit the
SQL statements. The default value for this
flag is
FALSE (0). This flag can be enabled only if
the system is licensed to use Temporal
Tables.
Default: ==> FALSE
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
56.
InclNTforGrntOrRevokAll - This field is to include
the nontemporal privilege in GRANT ALL,
REVOKE ALL
statements. If this field is false then
GRANT ALL
or REVOKE ALL will not include the
NONTEMPORAL
privilege. The default value is false.
This flag can be enabled only if the system
is
licensed to use Temporal Tables.
Default: ==> FALSE
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
57.
TimeDateWZControl - This field, when enabled, the
time
and time zone values returned by the built-in
functions CURRENT_TIME, CURRENT_TIMESTAMP,
and
CURRENT_DATE reflect the session time and
session
time zone. When this field is disabled, the
returned
time value reflects the local time of the
Teradata
Database server, however the returned time
zone value
reflects the session time zone. This field
will be disabled
by default after upgrade or sysinit when
dbscontrol
system timezone settings are zero but
enabled with value 2
for non-zero system timezone settings.
Valid values for this field are 1
(disabled),
2 (enabled with UTC i.e. all datetime data
is stored in UTC on disk), 3 (enabled with
LOCAL i.e.
datetime data without time zone is stored
in system LOCAL
time on disk) and 0 (returns the field to
disabled).
To perform operations on temporal tables,
this field
must be enabled.
Default: ==> 0
(after upgrade), 2 (after sysinit)
Recommended setting:
==> Default
Tpareset Required?
==> YES
58.
(Reserved for future use)
59.
SysinitRelease - This field displays the Major TDBMS Base Release on
which a Sysinit was last performed.
Recommended setting:
==> Cannot be modified
60.
DefaultCaseSpec - This field defaults character
comparisons to case specific in Teradata
mode.
It also defaults the char column to case
specific
when a table is created
The default value is FALSE.
Default: ==> FALSE
Recommended setting:
==> Customer preference (see Reference Article)
Tpareset Required?
==> YES
61.
PMPC_TimeoutSecs - This field specifies timeout interval in seconds
for certain supported PM API commands. The
default value is 60 seconds.
Valid range is 0 - 3600. Zero value
disables timeout, i.e., the response
for PM API request is returned only upon
the completion of its
processing.
Default: ==> 60
seconds
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
62.
ExportOrderBySegmentLimit - This field specifies the maximum number
of segments can be allocated for
FastExport's redistribution
when data is to be sorted.
The valid range is 500 to 2000. The default
value is 500.
Default: ==> 500
Reference Article:
==> N/A
Recommended setting:
==> Increase the value of this setting if a large, complex FastExport
job generates error 2587
Tpareset Required?
==> NO
63.
MLoadDiscardDupRowUPI - When IGNORE DUPLICATE ROWS is specified,
this flag indicates whether the DBS
MultiLoad protocol should
silently discard rows with UPI violations
or log these rows to
the application error (or UV) table.
The valid values are TRUE and FALSE. The
default is FALSE.
FALSE:
When IGNORE DUPLICATE ROWS is used, MultiLoad will log rows
with UPI violations to the
application error (or UV) table.
TRUE:
When IGNORE DUPLICATE ROWS is used, MultiLoad will
silently discard rows with UPI
violations. These rows
are not logged to application
error (or UV) table.
Default: ==> FALSE
Reference Article:
==> N/A
Recommended setting:
==> Customer preference
Tpareset Required?
==> NO
64.
DBQL CPU/IO Collection - This option modifies the manner in
which DBQL collects CPU/IO resource usage
data.
The default value of zero (0) (i.e. a value
has not been set)
means use the default value for the release
(Alg 1).
0 - Use default for this release
1 - Use V2R6 algorithm 1 with step
adjustments
2 - Use AMP algorithm 2 (mainly
diagnostic)
3 - Use AMP/DIS algorithm 3 (aborted &
parallel steps)
This change will become effective after the
DBS Control Record
has been written. Note that changing the
value from 3 to 1 or 2
does not free the existing AWTDPS cache in
each AMP until the
next
system restart.
Default: ==> 0
Recommended setting:
==> Default
Tpareset Required?
==> NO
65.
NoDot0Backdown - This field is used to prevent a backdown from
14.10 when a feature is used while running
on 14.10 that is
not supported on 14.00 and cannot be backed
out.
This field is FALSE by default on 14.00 and
cannot be changed
This field must be set to enable certain
14.10 features. Once
set this flag cannot be undone except by a
14.00 sysinit.
Default: ==> FALSE
(after upgrade), TRUE (after sysinit)
Reference Article:
==> N/A
Recommended setting:
==> Customer preference
Tpareset Required?
==> NO
66.
SnapBypassAggrCache - If TRUE snapshot dumps will be
suppressed
if resource exhaustion is detected when reserving
memory for aggregate processing.
WARNING: This might mask any real resource
leak issue in the system.
Default: ==> TRUE
Recommended setting:
==> Default
Tpareset Required?
==> NO
67.
Redrive Protection - Defines whether DBS should support Redrive
capability
0 -
Redrive Off; Redrive is not allowed
1 - Memory-based; Redrive protection for
DBS restarts and node
failures of non-PE nodes.
Default: ==> 0
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> YES
68.
Redrive Default Participation - Defines whether sessions participate
in Redrive if the session does not indicate
a preference at logon time.
0 - Redrive participation is off by
default. Sessions will not
participate
in Redrive unless they specifically
indicate at logon time they want
to participate in Redrive.
1 - Redrive participation is on by
default. Sessions will automatically
participate in Redrive unless they
specifically indicate at logon
time they do not want to participate in
Redrive.
Default: ==> 0
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> YES
69.
PMPC_SessionRateThreshold - This field specifies a threshold in
seconds for allowing Monitor Session cache
refresh on demand by
external applications when TDWM Workload
category is enabled.
This value is not used if TDWM Workload
category is disabled and
Monitor Session cache refresh is always
based on demand and
session rate.
Valid range is 0 - 600.
If the value is zero or exception interval
is higher than this
threshold value cache refresh on demand is
enabled, otherwise
monitor session cache is refreshed at
exception interval rate.
Default: ==> 60
Recommended setting:
==> Default
Tpareset Required?
==> NO
70.
RoundNumberAsDec - If TRUE indicates that the RoundHalfwayMagUp
flag will be honored for NUMBER data just
like for DECIMAL data.
if FALSE (default), NUMBER data will be
Rounded away from 0.
Default: ==> FALSE
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> YES
71.
DMLStatementShipping - This flag enables or disables replicating
SQL in lieu of change data for DML
statements, such as INSERT,
UPDATE, DELETE and MERGE. Valid values
are:
0 - Use default (Disabled)
1 - Enabled
2 - Disabled
Default: ==> 0
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
72.
SHOW IN XML Formatted Output - If TRUE it means that the output
XML document of SHOW IN XML statement is
pretty-printed with
indentation.
If FALSE (default), the output XML document
is an unbroken string
of text without indentation.
Default: ==> FALSE
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
73.
XML_MemoryLimit - Specifies the maximum amount of memory in MB that
can be used by XML operations. If a request
cannot be completed due
to this limit an out of memory error will
be returned to the user.
The default value is 4MB. Value range is 0
- 32.
Default: ==> 4MB
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
74.
DisplacementOnOverlap - This field is to treat transitional hour
different. When this field is 1 we use
standard displacement
for hour that repeats when DST ends and
when the field value is
2, we use daylight saving
displacement.
Default: ==> 0
(disabled)
Reference Article:
==> N/A
Recommended setting: ==>
Default
Tpareset Required?
==> NO
75.
NameValidationRule - This field specified the name validation rule
to be used when the object names are
created. The valid values are
0 (Default, no addition name validation),
1 (pre-EON LSM based validation),
2 (restricted set of character
validation(A-Z, a-z, 0-9, '$', '_', '#')),
62 (validation using UTF16 client character
set),
63 (validation using UTF8 client character
set),
64 (validation using EBCIDIC client
character set),
65-126 (validation using user defined
character set),
127 (validation using ASCII client
character set),
Default: ==> 0
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> YES
76.
EnableEON - This field allows the DBA to enable the functionality
of the EON feature.
The default value on freshly installed
system is true.
The default value on system upgrading to
14.10 is false.
-
This field may not be changed while NoDot0Backdown field is false.
-
Once set, this field cannot be modified back to false.
Default: ==>
TRUE(after sysinit) FALSE (after upgrade)
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
77.
DisableRecoverableNetProtocol - This field disables the Recoverable
Network Protocol. When this field is true the recoverable
network
protocol is disabled and a network
disconnect causes responses to
be dropped and transactions aborted for
gateway-attached clients.
Default: ==> FALSE
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
78.
DefaultCharacterSet - This field specifies the system default
for the character set option when it is not
specified in a
CREATE USER SQL statement. The valid values
are 0 (UNICODE)
and 1 (LATIN). 0 is default on Japanese
Language Support mode
systems and 1 is default on Standard
Language Support mode
systems. Enter 0 for setting to UNICODE and 1
for setting to
LATIN. The modification is effective after a
write. The modified
value
is used for new users created and does not impact existing
users in the system.
Default: ==> 0
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
79.
EnableLogonsMsg - This flag enables or disables the display
of 'Logons are enabled' message in
/var/log/messages on all
nodes of a Multi node system. If the flag
is set then the
message will be broadcasted to all the
nodes of the system.
If not set, the default behaviour of
logging the message on
the only node with control AMP will be
followed.
Default: ==> FALSE
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
82.
EnableJSON - This field enables or disables
the system-defined JSON type.
TRUE
- system-defined JSON type enabled (default)
FALSE - system-defined JSON type
disabled
Default: ==> TRUE
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> YES
83.
JSON_MaxDepth - This specifies the maximum depth of any JSON instance.
The default is 512, and the maximum is
32000.
Default: ==> 512
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
84.
JSON_AttributeSize - This specifies the maximum size of any attribute
returned by the JSONExtractValue method or
dot notation.
The default is 4096, and the maximum is
32000. To extract an attribute
larger than the maximum, please use the
JSONExtractLargeValue method.
Default: ==> 4096
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
86.
DisableJSONValidation - This field enables or disables
validation of the system defined JSON type.
TRUE
- disable validation of JSON type syntax
FALSE - enable validation of JSON type
syntax (default)
Default: ==> FALSE
Reference
Article: ==> N/A
Recommended
setting: ==> Default
Tpareset
Required? ==> YES
87.
FixSRandomRange - When TRUE fix the Random(lower_bound,
upper_bound) function to only produce
values within the bounds
specified. FixSRandomRange is unchanged for
upgrades and will be
FALSE initially. A SYSINIT sets the flag to
TRUE. The FALSE value
is only useful for Unity so the DBA can
apply the fix
simultaneously. In all other situations the
DBA should ensure
the flag is TRUE, although only Unity based
systems should be
affected.
Default: ==> TRUE on systems initialized (sysinited) on
Teradata Database15.0 or for which
this issue
with the RANDOM function has been fixed.
FALSE on systems upgraded from prior releases
and not re-initialized, where
this RANDOM issue still exists.
Reference
Article: ==> N/A
Recommended
setting: ==> If all systems being managed by Unity Director have
FixSRandomRange available in DBS control, it should be set to
TRUE on all systems. Otherwise, it should be set to FALSE on all
systems where the field is available.
Tpareset
Required? ==> NO
88.
Temporal Behavior - Valid values are 0 and 1. When set to 0, behavior
with temporal tables conforms to Teradata's
original temporal
implementation and syntax. When set to 1,
temporal behavior conforms to
ANSI/ISO standards. The default is 0 on systems
that have been upgraded
from systems where the Teradata Temporal
feature was enabled, otherwise
the default is 1.
Default: ==> 0 for
systems that were upgraded from releases prior to Teradata Database
Release 15.0,
and that had the Teradata Temporal feature enabled
1 for all other
systems.
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
DBS Control Record -
File System Fields:
1. FreeSpacePercent - This field is used by the
DBS and the File
System to determine the percentage of free
space to leave on
cylinders during bulk load operations. The
valid range of values
is 0 .. 75. The default value is 0
(percent).
Default: ==> 0%
Recommended setting:
==> Default (Customer tunable - see Reference Article)
Tpareset Required?
==> NO
2. MiniCylPackLowCylProd - This field is used by
the File System to
determine the number of free cylinders
below which it will start
to perform the "MiniCylPacks"
operation in anticipation of their
need. Setting this field to 0 indicates
that "MiniCylPacks" will
only be performed when no free cylinders
exist. The default value
is 10.
Default: ==> 10
Recommended setting:
==> Set this value to no more than 20 free cylinders
Tpareset Required?
==> NO
3. PermDBSize - This field is used by the File
System to determine the
maximum size of a Permanent Table's
multi-row Data Blocks in 512-byte
sectors. Setting the PermDBSize to 0 allows
the system to assume the
system default. The valid range of values
is 42 .. 2047. The default
value is 254 (sectors).
Default: ==> 254
Sectors
Recommended setting:
==> Default (Customer tunable - see Reference Article)
Tpareset Required? ==> NO
4. JournalDBSize - This field is used by the
File System to determine
the maximum size of Permanent Journal Table
multi-row Data Blocks
in 512-byte sectors. Setting the
JournalDBSize to 0 allows the system
to assume the system default. The valid
range of values is 42 .. 255.
The default value is 254 (sectors).
Default: ==> 254
Recommended setting:
==> Default (Customer tunable - see Reference Article)
Tpareset Required?
==> NO
5. DefragLowCylProd - This field is used by the
File System to determine
the number of free cylinders below which it
will start to perform
the "Cylinder defragmentation"
operation. Setting this field to 0
disables "Cylinder
defragmentation". The default value is 100.
Default: ==> 100
free cylinders
Recommended setting:
==> Default (Customer tunable - see Reference Article)
Tpareset Required?
==> NO
6. PermDBAllocUnit - This field is used by the
File System to determine
the allocation unit for Permanent Table's
multi-row Data Blocks in
units of 512-byte sectors. If a Permanent
Table Data Block contains
multiple rows, the size of the Data Block
will be a multiple of the
PermDBAllocUnit. The valid range of values
is 1 .. 127. The default
value is 1 (sector).
Default: ==> 1
sector
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> NO
7. CylindersSavedforPERM - This field is used to save X number
of cylinders for Perm Data only. If the number of Free cylinders
falls
below this value, any allocation of cylinders for Spool
Data will result in ERRFILDISKFULL. The
default value is 10.
Valid range is 1 .. 524287.
Default: ==> 10
cylinders
Recommended setting:
==> Default (Customer tunable)
Tpareset Required?
==> NO
8. DisableWALforDBs - This field is used to
force the writing of data
blocks directly to disk rather than writing
WAL records for them.
If DisableWALforDBs is FALSE, user table
data blocks are committed
to the WAL Log and cached in memory, or
written to disk, depending
on the specific operation. If
DisableWALforDBs is TRUE, user table
data blocks are always written to disk. The
default value is FALSE.
Default: ==> FALSE
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
9. DisableWAL - This field is used to force the
writing of data blocks
and cylinder indexes directly to disk
rather than writing WAL records.
Data blocks inserted by multiload always
are written to the disk.
If DisableWAL is FALSE, blocks are
committed to the WAL Log and
cached in memory, or written to disk,
depending on the specific
operation. If DisableWAL is TRUE, all
blocks are always written
directly to disk. The default value is
FALSE.
Default: ==> FALSE
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
10.
WAL Buffers - This field is used by the File System to determine the
number of WAL append buffers to allocate.
More buffers increase the
chance that when a task needs to append a
WAL record, there is an
available buffer to hold the row. Buffers
might be unavailable because
writes are pending, or they are full and a
write has not occurred.
If the system uses 1MB buffers and less
than 1536MB mem/AMP is available,
then the default number of buffers is
limited to 10.
Valid range is 5-40. The default value is
20.
Default: ==> 20
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> YES
11.
MaxSyncWALWrites - This field is used by the File System to determine
the maximum number of outstanding WAL Log
writes to allow before tasks
requiring synchronous writes are delayed to
achieve better buffering.
If the number of outstanding writes is less
than or equal to this
value, requests for synchronous operations
will append the record
to the current buffer, force a new buffer,
and issue a synchronous
write on the current buffer. If the number
of outstanding writes
is greater than this value, the record will
be appended but the
write will be delayed until one of the
outstanding writes completes.
Valid range is 1-40. The default value is
5.
Default: ==> 5
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> YES
12.
SmallDepotCylsPerPdisk - This field is used by the File System to
determine the number of DEPOT cylinders to
allocate that contain Small
DEPOT
slots of size 1MB. This number of cylinders is reserved
on each pdisk.
Default: 2 (cylinders)
Valid Range: 1-10
Effective: After TPA reset
Default: ==> 2
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> YES
13.
LargeDepotCylsPerPdisk - This field is used by the filesystem to
determine the number of DEPOT cylinders to
allocate that contain Large
DEPOT slots of size 1MB. This number of
cylinders is reserved on
each pdisk. Setting this field to 0
disables Large DEPOT usage.
Default: 1 (cylinders)
Valid Range: 0-10
Effective: After TPA reset
Default: ==> 1
Recommended setting:
==> Default
Tpareset Required?
==> YES
14.
WAL Checkpoint Interval - This field is used by the File System to
determine the amount of time that elapses
between WAL checkpoints.
Valid range is 1-240. The default value is
60 (seconds).
Changes made to its settings take effect
only after the GDO is written.
Default: ==> 60
seconds
Recommended setting:
==> Default
Tpareset Required?
==> NO
15.
Free Cylinder Cache Size - This field is
used by the File System to
determine how many cylinders are to be managed
in File System cache for
use as spool cylinders. NOTE - A value of 1
will disable use of the
cache. Valid range is 1 - 1000. Default is 100. Changes made to its
settings take effect only after system
restart.
Default: ==> 100
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> YES
16.
Bkgrnd Age Cycle Interval - This field is used by the File System to
determine the amount of time that elapses
between background cycles to
write a subset of modified segments in the
cache to disk. This background
activity serves to reduce the size of the
WAL log and promotes improved
disk space utilization in WAL modes. Valid
range is 1-240. The default
value is 60 (seconds).
Default: ==> 60
seconds
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
17.
DisableAutoCylPack - Indicates whether AutoCylPack is Disabled/Enabled.
When set to FALSE, AutoCylPack is enabled.
When set to TRUE, AutoCylPack is disabled.
Default is FALSE.
Changes made to its settings take effect
only after the GDO is written.
Default: ==> FALSE
Recommended setting:
==> Default
Tpareset Required?
==> NO
18.
AutoCylPackColdData - Indicates whether AutoCylPack works on cylinders
storing COLD data or not. Data that is
accessed infrequently is
classified as COLD data. When set to TRUE,
AutoCylPack works on COLD
cylinders. When set to FALSE, AutoCylPack
does not work on COLD
cylinders.
Default is FALSE.
This field is effective only if you have
purchased Teradata Virtual
Storage.
Default: ==> FALSE
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
19.
AutoCylPackFSP - Indicates the default target Free Space Percent (FSP)
for AutoCylPack. FSP is the proportion of
space that should not be
occupied by data on cylinders. For each
affected table, AutoCylPack
honors FSP settings in the following order
of precedence.
1. FSP specified in the CREATE or ALTER table
statement.
2. FSP specified during most recent Ferret
PACKDISK command.
3. FSP specified in this field, i.e.
AutoCylPackFSP.
Valid range is 10 - 75. Default is 10.
Default: ==> 10
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
20.
AutoCylPackStyle - Indicates the data migration style that AutoCylPack
is willing to perform in the process of
achieving target Free Space
Percent. If AutoCylPackStyle is:
1. Data will be moved to achieve an overall
increase in available space
per cylinder.
2. Data will be moved to achieve either an
overall increase or decrease
in available space per cylinder.
3. Data will be moved to achieve an overall
decrease in available space
per cylinder.
Valid range is 1 - 3. Default is 2.
Default: ==> 2
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
21.
AutoCylPackThresh - Indicates the variance between actual Free Space
Percent FSP) on a cylinder and the target
FSP for the cylinder above
which AutoCylPack will process the
cylinder. If the variance between
existing FSP of a cylinder and the target
is greater than
AutoCylPackThresh, AutoCylPack will process
the cylinder.
Otherwise, it will not.
Valid range is 5 - 30. Default is 5.
Default: ==> 5%
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
22.
AutoCylPackFreeCylThresh - Indicates the number of free cylinders
below which AutoCylPack will not operate.
The value of this field should
be greater than DBSControl field
MiniCylPackLowCylProd field.
This is to prevent AutoCylPack and MiniCylPack
working against each
other.
Valid range is 20 - 100. Default is 20.
Default: ==> 20
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
23.
AutoCylPackInterval - Indicates the amount of time
AutoCylPack sleeps between checks of
whether any cylinders need
processing. AutoCylPack sleeps if it completes
a pass of considering all
the cylinders represented in the MI, if it
runs into extreme lock
contention on CIs/DBs, or if the system stays
busy for a long time (see
help for AutoCylPackIOThresh).
Valid range is 60 - 600. Default is 60
seconds.
Default: ==> 60
seconds
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required? ==>
NO
24.
AutoCylPackIOThresh - Indicates the maximum number of outstanding I/Os
on a node above which AutoCylPack will
sleep for a short interval
before checking the outstanding I/O count
again.
It limits the performance impact of AutoCylPack
on the foreground work
load. If the system continues to stay busy,
AutoCylPack will sleep
according to the AutoCylPackInterval
defined.
Valid range is 1 - 1000. Default is 1.
Default: ==> 1
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
25.
(Reserved for future use)
26.
(Reserved for future use)
27.
MergeBlockRatio - This field is used by the File System when merging
datablocks together to determine the
maximum size of a newly merged
datablock. The value in this field is interpreted
as a percentage of the
maximum multi-row datablock size defined
for the table to which the
blocks belong. If no maximum multi-row size
is defined as a table-level
attribute, the value in this field is
interpreted a percentage of the
maximum multi-row datablock size as defined
in the field. For spool,
temporary, and WAL data, this value is not
used and merges are disabled.
For all other data, the value is only in
effect when 13.10 features are
enabled. Valid range is 0 - 100. The system
defined default value is 60
(percent). If 0 is entered, the value
reverts to the current system
defined default value.
Default: ==> 60%
Recommended setting:
==> Default
Tpareset Required?
==> NO
28.
DisableMergeBlocks - This field is used by the File System to determine
whether datablocks are eligible to be
merged together. If the value is
TRUE, then no datablocks in any tables will
ever be merged. I.e., the
MergeBlockRatio field is, and any
table-level MergeBlockRatio attribute
setting is also ignored. If the value is
FALSE and 13.10 features are
enabled, then the value in the
MergeBlockRatio field and/or table-level
MergeBlockRatio attributes are examined
determine the eligibility of
blocks to be merged together. The value is
FALSE.
Default: ==> FALSE
Recommended setting:
==> Default
Tpareset Required?
==> NO
29.
DisableRestartableBLC - This field is used by the File System and AMP
software to determine if Ferret BLC
operations will need to be
restartable or not. If the value of this
flag is TRUE, then Ferret BLC
operations are not restartable. That is,
Compress/Uncompress operations
will leave the table in partially
compressed state, if the system takes a
reset while Ferret compress/uncompress
operation is in progress. Also,
when this flag is TRUE, Ferret will not
allow the Compress/Uncompress
operations if there are downamp(s) in the
Ferret command scope.
If the DisableRestartableBLC flag value is
FALSE, then all allowed Ferret
BLC operations are restartable if a reset
occurs in the middle of the BLC
operation. That is, reset interrupted
Ferret Compress/Uncompress
operations will then be completed by the AMP
transaction recovery
mechansim. And Ferret also allows the Compress/Uncompress
operations with
downamp(s) in its scope.
The default value is FALSE.
Default: ==> FALSE
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required? ==> NO
30.
SpoolBigDBAllocUnit - This field is used by the File System to determine
the allocation unit for a multi-row Big
format datablock in a Spool table
in units of sectors. If a Big format Spool block is built, and if that
block contains contains multiple rows, then
the final size of the block
will be a multiple of the SpoolBigDBAllocUnit. The valid range of values
i 1 - 128 (sectors).
The default value is 1 (sectors).
Once modified, the value is effective after
a write.
Default: ==> 1
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
DBS Control Record -
Compression (Block Level) Fields:
1. BlockLevelCompression - This field controls
whether block level
compression is enabled globally or
not. Valid values are ON, to enable
compression, or OFF, to disable
compression.
If this field is ON, compression is enabled
or disabled for individual
table types as specified by their
corresponding tunables.
If this field is OFF, it supersedes all
table type specific settings.
Changes made to its settings take effect
after the GDO is written.
Default: ==> OFF
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
2. This field is reserved for future use.
3. CompressSpoolDBs - This field is used by the
File System to determine
how to handle Spool DBs with respect to
compression. This setting and
all other compression attributes specified
for the base table of this
table type also applies to sort and index
maintenance work subtables
and CLOB subtables corresponding to this
table type.
There are three values that are used,
ALWAYS, NEVER and IFNOTCACHED.
The default value is NEVER.
ALWAYS means that the data blocks of a new
Spool table will be
compressed.
NEVER means that the data blocks of a new
Spool table will not be
compressed.
IFNOTCACHED means that the data blocks of a
new Spool table will be
compressed if the DBs are not being cached.
Default: ==> NEVER
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
4. This field is reserved for future use.
5.
CompressMloadWorkDBs - This field is
used by the File System to
determine how to handle Multiload sort and
index maintenance work
subtables and CLOB subtables with respect
to compression.
There are three values that are used,
UNLESSQBNO, NEVER and ONLYIFQBYES.
The default value is NEVER.
compressed unless the Query Band option
specifies to compress them.
UNLESSQBNO means that the data blocks of a
new Mload work table will be
compressed unless the Query Band option
specifies not to compress them.
NEVER means that the data blocks of a new
Mload work table will not be
compressed regardless of what Query Band
options are specified.
Default: ==> NEVER
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
6. CompressPJDBs - This field is used by the
File System to determine
how to handle Permanent Journal DBs with
respect to compression. This
setting and all other compression attributes
specified for the base
table of this table type also applies to sort
and index maintenance work
subtables and CLOB subtables corresponding
to this table type.
There are two values that are used, ALWAYS
and NEVER. The default is
NEVER.
ALWAYS means that the data blocks of a new
PJ table will be compressed.
NEVER means that the data blocks of a new
PJ table will not be
compressed.
Changes made to its settings take effect
after the GDO is written.
Default: ==> NEVER
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
7. MinDBSectsToCompress - A parameter to be used
by the compression.
algorithm to determine if enough sectors
exist in the Data Block
to warrant compression. If not enough sectors exist in the Data
Block,
the Data Block will not be saved in the
compressed format.
The allowable range is 32 to 2047.
Changes made to its settings take effect
after the GDO is written -
but only for newly compressed data,
existing compressed data stays as is
until modified.
Default: ==> 32
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
8. MinPercentCompressReduction - A parameter to
be used by the compression
algorithm to determine if compression of
the Data Block has reduced the
size a sufficient amount. If the size
reduction is not adequate, the
Data Block will not be saved in the
compressed format.
The allowable range is 0 to 99 with a
default of 20
Changes made to its setting take effect
only after the GDO is written.
Default: ==> 20%
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
9. CompressionAlgorithm - A parameter indicating
which algorithm to use for
compression/decompression. 'ZLIB', 'ELZS_H' and 'ELZS_S' are the
algorithms supported. The default is 'ZLIB'. If ELZS_H is selected and
the board is absent, ELZS_S will
automatically be used. ELZS_S is not a
recommended selection unless the hardware
is suspect. Before choosing
ELZS_H or ELZS_S, please ensure all nodes
have the requisite support
installed. If some node lacks support,
unanticipated behavior can be
expected.
o Data qualifying for compression will
not be compressed.
o Data already compressed previously
via ELZS algorithms (perhaps
present from a restore from a system that had
support) will cause
the task accessing the data to be aborted
when trying to
decompress the data.
Changes made to its settings take effect
after the GDO is written – but
only for newly compressed data, existing
compressed data stays as is
until modified.
Default: ==> ZLIB
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
10.
CompressLevel - A parameter used by the selected compression algorithm.
For ZLIB, valid values are from 1 thru 9.
A value of 1 indicates preference for
maximum compression speed.
Each higher values sacrifices more speed
for better compression ratio.
The highest value of 9 optimizes for
minimal compression size.
The default value is 6, a balance between
speed and size.
Changes made to its setting take effect
only after the GDO is written -
but only for newly compressed data, existing
compressed data stays as is
until modified.
Default: ==> 6
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
11.
(Reserved for future use)
12.
UncompressReservedSpace - Specifies a percentage value indicating
the minimum amount of free space that
should be left in a database
when performing an uncompress operation. If there is not sufficient
space the uncompress operation will be
terminated and the table left
in a partially compressed state (but still
usable).
Allowable range is 0 to 90(percent) with a
default of 5.
Changes made to its settings take effect
after the GDO is written.
Default: ==> 5%
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
13.
This field is reserved for future use.
14.
CompressPermPrimaryDBs - This field is used by the File System to
determine how to handle primary subtable datablocks
in Permanent storage
of tables using manual compression. This field does not affect tables
using automatic compression. System data, dictionary data, table
headers, LOBs (except CLOBs), Snapshot
Logs, Restore Logs, and all
primary row secondary indexes are always
excluded from compression.
This setting and all other compression attributes
specified for the base
table of this table type also apply to sort
worktables and index
maintenance worktables corresponding to
this table type.
ONLYIFQBYES means that the datablocks of a
new subtable will not be
compressed unless a Query Band option is
provided that specifies to
compress them.
UNLESSQBNO means that the datablocks of a
new subtable will be
compressed unless a Query Band option is
provided that specifies not to
compress them.
NEVER means that the datablocks of a new
subtable will not be compressed
regardless of any specified Query Band
option.
The default value is ONLYIFQBYES.
Default: ==>
ONLYIFQBYES
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
15.
CompressPermFallbackDBs - This field is used by the File System to
determine how to handle fallback subtable
datablocks in Permanent
storage of tables using manual compression. This field does not affect
tables using automatic compression. System data, dictionary data, table
headers, LOBs (except CLOBs), Snapshot
Logs, Restore Logs, and all
primary row indexes are always excluded
from compression. This setting
and all other compression attributes
specified for the base table of
this table type also apply to sort
worktables and index maintenance
worktables corresponding to this table
type.
ONLYIFQBYES means that the datablocks of a
new subtable will not be
compressed unless a Query Band option is
provided that specifies to
compress them.
UNLESSQBNO means that the datablocks of a
new subtable will be
compressed unless a Query Band option is
provided that specifies not to
compress them.
NEVER means that the datablocks of a new
subtable will not be compressed
regardless of any specified Query Band
option.
The default value is ONLYIFQBYES.
Default: ==>
ONLYIFQBYES
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
16.
CompressPermPrimaryCLOBDBs - This field is used by the File System to
determine how to handle primary CLOB
subtable datablocks in Permanent
storage of tables using manual compression.
This field does not affect
tables using automatic compression. System
data, dictionary data, table
headers, LOBs (except CLOBs), Snapshot
Logs, Restore Logs, and all
primary row secondary indexes are always
excluded from compression.
This setting and all other compression attributes
specified for the base
table of this table type also apply to sort
worktables and index
maintenance worktables corresponding to
this table type.
ONLYIFQBYES means that the datablocks of a
new subtable will not be
compressed unless a Query Band option is
provided that specifies to
compress them.
UNLESSQBNO means that the datablocks of a
new subtable will be
compressed unless a Query Band option is
provided that specifies not to
compress them.
NEVER means that the datablocks of a new
subtable will not be compressed
regardless of any specified Query Band
option.
The default value is NEVER.
Default: ==> NEVER
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
17.
CompressPermFallbackCLOBDBs - This field is used by the File System to
determine how to handle fallback CLOB
subtable datablocks in Permanent
storage of tables using manual compression. This field does not affect
tables using automatic compression. System data, dictionary data, table
headers,
LOBs (except CLOBs), Snapshot Logs, Restore Logs, and all
primary row secondary indexes are always
excluded from compression.
This setting and all other compression attributes
specified for the base
table of this table type also apply to sort
worktables and index
maintenance worktables corresponding to
this table type.
ONLYIFQBYES means that the datablocks of a
new subtable will not be
compressed unless a Query Band option is
provided that specifies to
compress them.
UNLESSQBNO means that the datablocks of a
new subtable will be
compressed unless a Query Band option is
provided that specifies not to
compress them.
NEVER means that the datablocks of a new
subtable will not be compressed
regardless of any specified Query Band
option.
The default value is NEVER.
Default: ==> NEVER
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
18.
CompressGlobalTempPrimaryDBs - This field is used by the File System to
determine how to handle primary subtable
datablocks in Global Temporary
storage with respect to compression. System data, dictionary data,
table headers, LOBs (except CLOBs), Snapshot
Logs, Restore Logs, and all
primary row secondary indexes are always
excluded from compression.
This setting and all other compression attributes
specified for the base
table of this table type also apply to sort
worktables and index
maintenance worktables corresponding to
this table type.
ONLYIFQBYES means that the datablocks of a
new subtable will not be
compressed unless a Query Band option is
provided that specifies to
compress them.
UNLESSQBNO means that the datablocks of a
new subtable will be
compressed unless a Query Band option is
provided that specifies not to
compress them.
NEVER means that the datablocks of a new
subtable will not be compressed
regardless of any specified Query Band
option.
The default value is NEVER.
Default: ==> NEVER
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
19.
CompressGlobalTempFallbackDBs - This field is used by the File System to
determine how to handle fallback subtable
datablocks in Global Temporary
storage with respect to compression. System data, dictionary data,
table headers, LOBs (except CLOBs), Snapshot
Logs, Restore Logs, and all
primary row secondary indexes are always
excluded from compression.
This setting and all other compression attributes
specified for the base
table of this table type also apply to sort
worktables and index
maintenance worktables corresponding to
this table type.
ONLYIFQBYES means that the datablocks of a
new subtable will not be
compressed unless a Query Band option is
provided that specifies to
compress them.
UNLESSQBNO means that the datablocks of a
new subtable will be
compressed unless a Query Band option is
provided that specifies not to
compress them.
NEVER means that the datablocks of a new
subtable will not be compressed
regardless of any specified Query Band
option.
The default value is NEVER.
Default: ==> NEVER
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
20.
CompressGlobalTempPrimaryCLOBDBs - This field is used by the File System
to determine how to handle primary CLOB
subtable datablocks in Global
Temporary storage respect to
compression. System data, dictionary
data,
table headers, LOBs (except CLOBs), Snapshot
Logs, Restore Logs, and all
primary row secondary indexes are always
excluded from compression.
This setting and all other compression attributes
specified for the base
table of table type also apply to sort
worktables and index maintenance
worktables corresponding to this table
type.
ONLYIFQBYES means that the datablocks of a
new subtable will not be
compressed unless a Query Band option is
provided that specifies to
compress them.
UNLESSQBNO means that the datablocks of a
new subtable will be
compressed unless a Query Band option is
provided that specifies not to
compress them.
NEVER means that the datablocks of a new
subtable will not be compressed
regardless of any specified Query Band
option.
The default value is NEVER.
Default: ==> NEVER
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
21.
CompressGlobalTempFallbackCLOBDBs - This field is used by the File
System to determine how to handle fallback
CLOB subtable datablocks in
Global Temporary storage with respect to
compression. System data,
dictionary data, table headers, LOBs
(except CLOBs), Snapshot Logs,
Restore Logs, and all primary row secondary
indexes are always excluded
from compression. This setting and all other compression
attributes
specified for the base table of this table
type also apply to sort
worktables and index maintenance worktables
corresponding to this table
type.
ONLYIFQBYES means that the datablocks of a
new subtable will not be
compressed unless a Query Band option is
provided that specifies to
compress them.
UNLESSQBNO means that the datablocks of a
new subtable will be
compressed unless a Query Band option is
provided that specifies not to
compress them.
NEVER means that the datablocks of a new
subtable will not be compressed
regardless of any specified Query Band
option.
The default value is NEVER.
Default: ==> NEVER
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
22
- 31. (Reserved for future use)
32.
EnableTempBLC - Controls all parts of temperature based BLC
This includes the AutoTempComp background
task responsible for
compressing and uncompressing data based on
temperature, and any
decisions to automatically compress COLD
data as it is loaded.
If this value is enabled, it is highly
recommended that the
tunable
DisableAutoCylPack be set to FALSE and AutoCylPackColddata
be set to TRUE. If set to FALSE, the rules for compression
revert
to the inheritance model used by tradional
BLC(if enabled).
EnableTempBLC might be set to FALSE during
a performance critical
window.
Valid Values are TRUE and FALSE. The default is FALSE. Changes are
effective immediately.
Default: ==> FALSE
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
33.
DefaultTableMode - Indicates whether the default for permanent tables
with no specific table level attribute is
to manage their compression
manually, automatically or never compress
the table. If MANUAL
is chosen, it is the user's responsibility
to compress or
decompress the table. If AUTOTEMP is chosen, then data in the
table will be compressed or decompressed
automatically by the
AutoTempComp background task based on the
temperature of the data.
In this mode, parts of the table(such as
partitions) may have a
different compression state based on their
frequency of access.
If NEVER is chosen, then data in the table
will never be compressed.
Valid values are MANUAL, AUTOTEMP and
NEVER. The default is
MANUAL.
Changes are effective immediately.
Default: ==> MANUAL
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
34.
TempBLCThresh - Indicates the temperature threshold at which data in
tables using AUTOTEMP compression
management are compressed. Any
data at or colder than the specified
temperature will be compressed.
Temperatures can be specified by keyword or
a floating point value
representing a percentage of the coldest
allocated
user data (PERM TABLES) that should be
compressed. The percentage is
calculated based on the number of cylinders
of PERM data used,
without regard to how fully occupied the
cylinders are.
Valid Values are COLD, WARM, HOT, or a
floating point value greater
than 0 and less than or equal to 100. The default is COLD.
Changes are effective immediately.
Default: ==> COLD
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
35.
TempBLCSpread - A percentage that is added to or subtracted from
TempBLCThresh to determine if a cylinder
should change compression state.
For example, if the TempBLCThresh is
defined as COLD and the
TempBLCSpread is 5% then the data must be
5% colder than COLD to be
compressed and 5% warmer than COLD to be uncompressed. This value can be
used to prevent whose natural temperature
is close to the threshold from
being repeatedly compressed and
uncompressed. Valid values are from 1 to
25%. default is 5%. Changes are effective immediately.
Default: ==> 5%
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
36.
TempBLCInterval - The amount of time for AutoTempComp to wait after
compressing or uncompressing data before
checking if other data
needs to be processed. If the whole MI is scanned and no data is
found to process then AutoTempComp will
sleep for a duration
indicated by TempBLCRescanPeriod.
Valid values are from 1 to 120
minutes. The default is 10 minutes.
Changes are effective the next time
AutoTempComp wakes up.
Default: ==> 5%
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
37.
TempBLCIOThresh - The maximum number of outstanding I/O's on a node
above which AutoTempComp will sleep for a
short interval before running
again.
This setting limits the performance impact of AutoTempComp
on
foreground work loads. If the system
remains busy, AutoTempComp
will sleep according to the TempBLCInterval
setting.
Valid values are from 1 to 1000. The default is 1. Changes are
effective immediatelly.
Default: ==> 1
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
38.
TempBLCPriority - The priority at which AutoTempComp runs. Priorities
can be specified using their old or new
names.
Valid values are: LOW, MEDIUM (or DEFAULT),
HIGH,
or RUSH(or TOP). The default is MEDIUM (or DEFAULT). Changes are
effective the next time AutoTempComp wakes
up.
Default: ==> MEDIUM
/DEFAULT
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
39.
TempBLCRescanPeriod - The length of time in days to allow before
revalidating the state of cylinders using
automatic compression to
see if they are properly compressed or
uncompressed. This rescan is
necessary as the temperature of a cylinder
can change, even if the
cylinder is not directly modified. At least one scan is performed
after each startup.
Valid values are from 1 to 90 days. The default is 7 days.
Changes are effective the next time
AutoTempComp wakes up.
Default: ==> 7
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
40.
CompressionZLIBMethod - This field specifies specific ZLIB implementation
package to use. If the package is not
installed or error is encountered,
ZLIB is used instead.
ZLIB - Standard ZLIB is used for
compression/uncompression (default)
IPPZLIB - Intel's IPP ZLIB implementation
Default: ==> ZLIB
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
DBS Control Record -
Performance Fields:
1. DictionaryCacheSize - This field defines the
size of the dictionary
cache for each PE Vproc on the system. The
valid range of values
is 64 .. 32768. The default value is 8192
(kilobytes).
Default: ==> 8192 KB
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> YES
2. DBSCacheCtrl - This field is used to enable
or disable the performance
enhancements associated with Cache Control
Page-Release Interface. The
default value is TRUE.
Default: ==> TRUE
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
3. DBSCacheThr - This field is used to specify
the percentage value to
use to calculate the cache threshold when
the DBSCacheCtrl field is
enabled. The valid range of values is 0 ..
100. The default value
is 10.
Default: ==> 10%
Recommended setting:
==> 1% (see Reference Article)
Tpareset Required?
==> NO
4. MaxParseTreeSegs - This field defines the
maximum number of tree
segments that the parser will allocate
while parsing a request. The
valid range of values is 12 .. 12000. The
default value is 2000.
32-bit platform, the default is 1000.
The size of each tree segment in KBytes can
be tunable by a TD field
representative. The current value is 512
and the total current memory
available is 6144000 KBytes.
Default: ==> 32bit =
1000 Range = 12 to 6000
64bit = 2000
Range = 12 to 12000
Reference Article:
==> N/A
Recommended setting:
==> Default (Change only under the direction of Teradata Support
Center)
Tpareset Required?
==> NO
5. ReadAhead - This field is used to enable or
disable the performance
enhancements associated Read-Ahead
Sequential File Access Workload.
The default value is TRUE.
Default: ==> TRUE
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> NO
6. StepsSegmentSize - This field defines the
maximum size of the plastic
steps segment (aka "OptSeg") in
kilobytes. The valid range of values
is 64 .. 1024. The default value is 1024
(kilobytes).
Default: ==> 1024
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> NO
7. RedistBufSize - This field determines the
size (in bytes/kilobytes)
of hashed row redistribution buffers used
by MultiLoad, FastLoad,
Create Unique Index, and SMP-only SQL step
responses. Each such
redistribution in an AMP will use one such
buffer for each AMP in
the configuration. The ranges of valid
values are:
-1: the optimal buffer size to
avoid extra memory overhead
for sending row
redistribution messages on the
current system (3832
bytes).
0: the default buffer size
for current system (3832 bytes).
1 .. 63: the buffer size in units
of kilobytes. The buffer size
in this value range may be
adjusted internally
for better memory
utilization.
512 .. 65024: the buffer size in units
of bytes, which is equivalent
to 0.5 .. 63.5 kilobytes.
The buffer size in this
case is used exactly as is
without further adjustment.
The default value is 3832 bytes.
Default: ==> 3832
bytes
Recommended setting:
==> Default (Customer tunable, see Reference Article)
Tpareset Required?
==> NO
8. DisableSyncScan - This field enables or
disables the performance
enhancements associated with synchronized
full table scans. A value
of F enables the feature. A value of T disables the feature.
The default is FALSE.
Default: ==> FALSE
Recommended setting:
==> Default (See Reference Article)
Tpareset Required?
==> YES
9. SyncScanCacheThr - This field specifies the
percentage of file system
(FSG) cache that the Teradata file system
can assume is available for
synchronized scans of tables. It does not reserve cache for this
purpose.
Instead, this value specifies the amount of permanent data
the Teradata file system should try to
retain in memory at any one
time for all tables involved in
synchronized scans. Whether that
much memory is truly available depends on
actual workload. The valid
range
of values is 0 .. 100, where 0 indicates that the default value
should be used. The default value is 10.
Changes that are made to its settings take
effect only after the GDO is
written.
Default: ==> 10%
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> NO
10.
HTMemAlloc - This field specifies the percentage of memory to be
allocated to a hash table for a hash
join. A value of 0 turns off
hash joins. Valid range is 0 to 10.
The default value is 10.
The default value for 32-bit platform is 2.
Default: ==> 32bit =
2; 64bit = 10
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> NO
11.
SkewAllowance - This field specifies a percentage factor used by the
optimizer in deciding on the size of each
hash join partition. It makes
allowance for data skew in the build
relation. Valid range is 20 to 80.
The default value is 75.
Default: ==> 75%
Recommended setting:
==> Default (See Reference Article)
Tpareset Required?
==> NO
12.
Read Ahead Count - If the ReadAhead field is set TRUE,
ReadAhead Count is used to specify the
number of data blocks
that will be preloaded in advance of the
current file
position while performing sequential
scans. The valid range
of values is 1 .. 100. The default value is
1.
Default: ==> 1 DB
Recommended setting:
==> Default (See Reference Article)
Tpareset Required?
==> NO
13.
PPICacheThrP - This field specifies the maximum amount of FSG memory
to be used, in tenths of a percent of
available FSG memory, for disk read
operations dealing with multiple
partitions.
If the amount of available FSG memory per
AMP exceeds 100 MB,
the threshold will be calculated based on
100 MB per AMP.
The valid range is 0 to 500 (that is, 0% to
50.0%).
The default value is 10 (that is, 1.0%).
Default: ==> 10
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> NO
14.
ReadLockOnly - This field is used to disable or enable the special
read-or-access lock protocol on 1)
DBC.AccessRights table during access
rights validation and on 2) dictionary
tables accessed by read-only
queries during request parsing. The default value is FALSE.
Default: ==> FALSE
Recommended setting:
==> Default (See Reference Article)
Tpareset Required?
==> NO
15.
IAMaxWorkloadCache - This tunable field defines the maximum size in
megabytes of the workload cache used by
Index Wizard Analysis.
Valid range is 64 to 187. The default value
is 64 (megabytes).
Default: ==> 64MB
Recommended setting:
==> Default (See Reference Article)
Tpareset Required?
==> NO
16.
MaxRequestsSaved - This field governs the number of
request cache entries allowed on a PE. The
default
number of entries that can be saved in the
cache
is 600. The user can modify this field to a
fixed
value that ranges from 300 to 2000 and, is
a multiple
of 10.
Default: ==> 600
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> YES
17.
UtilityReadAheadCount - Specifies the number of data blocks the
Teradata utilities will preload at a time
while it performs its
sequential scan. The utilities uses this field instead of the
ReadAhead
and ReadAhead Count fields. The valid range of values is 1 .. 100.
The default value is 10 (blocks).
Default: ==> 10
blocks
Recommended setting:
==> Default
Tpareset Required?
==> NO
18.
StandAloneReadAheadCount - Specifies the number of data blocks to
preload when File System startup or a
utility runs as a standalone
task.
The valid range of values is 1 ..
100.
The default value is 20 (blocks).
Default: ==> 20
blocks
Recommended setting:
==> Default
Tpareset Required?
==> NO
19.
DisablePeekUsing - This field enables or disables the
performance enhancements associated with
exposed using values.
A value of F enables the feature. A value
of T disables the
feature. The default value is F (FALSE).
Default: ==> FALSE
Recommended setting: ==>
Default (see Reference Article)
Tpareset Required?
==> NO
20.
IVMaxWorkloadCache - This tunable field defines the maximum size in
megabytes of the workload cache used by
Index Wizard Validation.
Valid range is 1 to 32. The default value
is 1 (megabytes).
Default: ==> 1
Recommended setting:
==> Default
Tpareset Required?
==> NO
21.
RevertJoinPlanning - Setting this to T (TRUE) causes join planning
to use a fixed 64 table limit for joins and
TD12 join planning
heuristics.
Valid range - T, F
Default - F
Default: ==> FALSE
Recommended setting:
==> Default
Tpareset Required?
==> NO
22.
MaxJoinTables - The maximum number of tables allowed in a join. 0 is
mapped to the default value, and any value
in 1..16 is mapped to 16.
Valid range - 0..128
Default - 128
Default: ==> 0 (128)
Recommended setting:
==> Default
Tpareset Required?
==> NO
23.
DBQLXMLPlanMemLimit - Sets the maximum amount of memory in kilobytes
the XML document can use per request. If
the size of a document exceeds
this value, then the document will only
contain the error message.
The valid range of values is 0 .. 128000.
A value of 0 disables memory limit checking
of the XML document.
The minimum recommended value is 8192.
The default value is 64000.
Default: ==> 64000
KB
Recommended setting:
==> Default
Tpareset Required?
==> NO
24.
LimitInlistCVal - This field limits the number of combined values in
Inlist.
The valid range of values is 1 .. 1048576.
The default value is 1048576.
Default: ==> 1048576
Recommended setting:
==> Default
Tpareset Required?
==> NO
25.
NumStatisticsCacheSegs - This field defines the number of segments for
the statistics cache maintained at each PE
Vproc on the system. The valid
of values is 2 .. 200. The default value is
5. The default size of the
each segment is 1024KB.
Default: ==> 5
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> YES
26.
SHOW IN XML Memory Limit - Sets the maximum amount of memory in kilobytes
used for internal processing of a request
of SHOW IN XML statement.
If the amount of memory needed by a request
exceeds this value, an error
message will be returned.
The valid range of values is 8192 ..
128000.
The default value is 64000.
Default: ==> 64000
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
27.
DictionaryCacheSegmentSize - This field defines the segment size of the
dictionary cache in multiples of 64 KBs for
each PE Vproc on the
system. The valid range of values is 0 ..
256. The default value
is 16 .
Default: ==> 16
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> YES
28.
PRPDMaxSkewedVals - This field determines at most how many loners could
be considered for PRPD plan. The value
range for this field is [1, 500].
Default: ==> 50
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
29.
PRPDSkewPct - This field represent the percentage of rows to be
considered for skew and will be used to find
the number of skewed values
to be picked for split conditions.
Default: ==> 50
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
30.
DBQLLOBCacheSize - This field determines the size of cache being
allocated for DBQL dictionary tables with
LOB columns. Value can range
from 2 to 16. Unit of cache size is MB.
This parameter also affects the
size of express message to flush this cache.
It is recommended to keep
this value at default.
Default value is 2. Note that any modification
to this field will be
effective only after database restart.
Increasing this cache size helps
capture larger requests and reduce number
of flushes when the cache fills
up. On the other hand, it will increase
express request message size when
flushing. When increasing this value, above
mentioned pros and cons need
to be considered.
Default: ==> 2 MB
Reference Article:
==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> YES
DBS Control Record -
Disk I/O Integrity (Checksum) Fields:
CHECKSUM
LEVELS
1. System Tables - This field is used to set the
checksum level
of system tables
(data dictionaries, session
information,
etc.).
2. System Journal Tables - This field is used to set the checksum
level
of system journal
tables (transient journal,
change tables,
recovery journals).
3. System Logging Tables - This field is used to set the checksum
level
of system
logging tables (RSS tables,
accounting
tables, etc.).
4. User Tables - This field is used to set the
checksum level
Of user tables
(includes stored procedures,
user-defined
functions, join indexes, hash
indexes).
5. Permanent Journal Tables - This field is used
to set the checksum level
of permanent
journal tables.
6. Temporary Tables - This field is used to set the
checksum level
of temporary and
spool tables.
Valid
values for these fields are NONE, LOW, MEDIUM, HIGH, and ALL. The
default
is NONE.
NOTE: Modifying field 0 results in setting fields 1
- 6 to the specified
value.
CHECKSUM
LEVEL DEFINITIONS
NONE
- Do not calculate checksums
(sample 0% of the disk block to
generate a checksum). This percentage cannot be modified.
7. LOW
- Calculate checksums by sampling
a low percentage of the disk
block. Default is to sample 2% of the disk
block. Valid range
is 1 - 100%.
8. MEDIUM -
Calculate checksums by sampling a medium percentage of the disk
block. Default is to sample 33% of the disk
block. Valid
range is 1 - 100%
9. HIGH
- Calculate checksums by sampling
a high percentage of the disk
block. Default is to sample 67% of the disk block. Valid
range is 1 - 100%
ALL
- Calculate checkums using the
entire disk block (sample 100% of
the disk block to generate a
checksum). This percentage cannot
be modified.
Default: ==> NONE
Recommended setting:
==> Default (see Reference Article)
Tpareset Required?
==> NO
DBS Control Record -
Optimizer Statistics Fields:
1.
DefaultTimeThreshold - This field
defines a default time threshold value
in days for statistics recollection. This
setting is applicable only if
the COLLECT STATISTICS statement does not
specify USING THRESHOLD DAYS.
The valid range is between 0 and 9999. A
value of 0 which is the default
value indicates time threshold checking is
disabled.
Default: ==> 0
Reference Article:
==> N/A
Recommended setting: ==> Default
Tpareset Required?
==> NO
2.
DefaultUserChangeThreshold - This field
defines a default data change
percentage threshold value for statistics
recollection. This setting is
applicable only if the COLLECT STATISTICS
statement does not specify
USING THRESHOLD PERCENT. The valid range is
between 0 and 9999. A value
of 0 which is the default value indicates
user change threshold checking
is disabled. Note that if the DBQL ObjectUsage
logging is not enabled,
the change percentage to skip statistics
collection is determined based
on dynamic AMP sampling (which can only
detect the row count change).
Default: ==> 0
Reference Article:
==> N/A
Recommended setting: ==>
Default
Tpareset Required?
==> NO
3.
SysChangeThresholdOption - This field
defines a change threshold option
for statistics recollection. This setting
is applicable only if
DefaultUserChangeThreshold is disabled and
the COLLECT STATISTICS
statement does not specify USING THRESHOLD
PERCENT. Valid settings are as
follows:
- 0: System default (same as a setting of
1)
- 1: Enable system-determined change
threshold checking in statistics
collection only when DBQL ObjectUsage
(update/delete/insert counts)
is enabled.
- 2: Enable system-determined change
threshold checking (regardless
of ObjectUsage setting in DBQL logging
options) in statistics
collection.
- 3: Disable system-deterined change
threshold checking.
Default: ==> 0
Reference Article: ==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
4.
SysSampleOption - This field defines a
sample option for statistics
recollection. This setting is applicable
only if the COLLECT STATISTICS
statement does not specify USING SAMPLE.
Valid settings are as follows:
- 0: System Default (same as a setting of
1)
- 1: Enable system-determined sample
percentage up to 100%.
- 2: Sample percentage is 100% (full
statistics).
Default: ==> 0
Reference Article: ==> N/A
Recommended setting:
==> Default
Tpareset Required?
==> NO
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