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
Reference Article: ==> See Utilities manual
Recommended setting: ==> FALSE
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
Reference Article: ==> See Utilities manual
Recommended setting: ==> Customer tunable
Tpareset Required? ==> NO
15. DateForm - This field defines whether
IntegerDate (0)
or ANSIDate (1) is used for a
session.
Default: ==> (0) IntegerDate
Reference Article: ==> See Utilities manual
Recommended setting: ==> Customer
preference
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
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
Reference Article: ==> KAP3BD24E
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
a Target Level 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. External Authentication - 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. IdColBatchSize - 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.
Default: ==> MPRAS = /var/tdrsg; Linux =
/opt/teradata/tdat/temp/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. It cannot be changed.
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, if the system timezone
settings are zero and enabled with 2 for non-zero 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: ==> See Utilities manual
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: ==> FALSE
Reference Article: ==> DR149835
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 partication 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 partication 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
Reference Article: ==> DR146269
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 system default. 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 impacted existing users in the system.
Default: ==> 0
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 .. 255. 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. 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
Reference Article: ==> KAP245F12
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.
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 slots of size 128KB.
This number of cylinders is
reserved on each pdisk. Valid range is 1-10.
The default value is 2.
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 slots of size 512KB.
This number of cylinders is
reserved on each pdisk. Valid range is 0-10.
Setting this field to 0 disables
large depot usage. The default value is 1.
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
FSP 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
as a percentage of the maximum
multi-row datablock size as defined in the
PermDBSize 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
ignored, 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
to determine the eligibility of
blocks to be merged together. The default 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. The above behavior with the
flag
value of TRUE, is same for both TRUE or FALSE states of NoDot0BackDown flag.
If
the DisableRestartableBLC flag value is FALSE and NoDot0Backdown is TRUE, 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 Fields:
Note on Compression:
Block Level Compression (BLC) enables data
compression at the data block (DB)
level of the Teradata Database file system.
Compression reduces the amount of
storage required for a given amount of data.
BLC increases CPU utilization for
dynamic compression and decompression
operations, which can result in reduced
performance. However, in some situations, BLC
can improve database performance
due to reduced I/O bandwidth.
Compression can be enabled or disabled
entirely, or for various categories of
tables. Only primary, fallback, and CLOB
subtables, and join and hash indexes
are subject to compression. Secondary indexes
are never compressed.
The PermDBSize and JournalDBSize settings in
DBS Control apply to the sizes of
uncompressed DBs.
Note: Compression
is subject to the BlockLevelCompression setting, and to the
criteria specified by the MinPercentCompReduction and
MinDBSectsToCompress DBS
Control settings. DBs not meeting these
minimum criteria will not be compressed.
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
tables with respect to
compression.
There are three values
that are used, UNLESSQBNO, NEVER and ONLYIFQBYES.
The default value is
ONLYIFQBYES.
ONLYIFQBYES means that the
data blocks of a new table will not be
compressed unless the
Query Band option specifies to compress them.
UNLESSQBNO means that the
data blocks of a new table will be compressed
unless the Query Band
option specifies not to compress them.
NEVER means that the data
blocks of a new 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 tables
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 table will be compressed.
NEVER means that the data
blocks of a new 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 255.
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. This field is 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
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
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
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
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 data whose natural temperature is close to the threshold
from
being repeatedly compressed and uncompressed.
Valid values are from 1 to 25%.
The 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 /DEAUL
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
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 128 and the total current memory
available is 256000 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 for 64-bit platform 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. ReadAhead 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
range 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
DBS Control Record - Disk I/O Integrity 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
log 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 checksums 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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