Comparison of the Teradata loading utilities

Comparison of the Teradata loading utilities

The article contains comparison and main features of the data loading tools provided by Teradata. The tutorial illustrates main features of Teradata Multiload , FastLoad and TPump (Parallel Data Pump) and provides sample real-life uses of those tools.

Scroll down for the sample scripts which illustrate different ways to load a sample fixed-length extract into a Teradata database using FastLoad, MultiLoad and Parallel Data Pump (TPump).

Teradata Fast Load

  Main use: to load empty tables at high speed.

  The target tables must be empty in order to use FastLoad

  Supports inserts only - it is not possible to perform updates or deletes in FastLoad

  Although Fastload uses multiple sessions to load the data, only one target table can be processed at a time

  Teradata Fastload does not support join indexes, foreign key references in target tables and tables with secondary index defined. It is necessary to drop any of the constraints listed before loading and recreate them afterwards.

  The maximum number of concurrent Teradata Fastload tasks can be adjusted by a system administrator.

  Fastload runs in two operating modes: Interactive and Batch

  Duplicate rows will not be loaded

Teradata Multi Load

  Main use: Load, update and delete large tables in Teradata in a bulk mode

  Efficient in loading very large tables

  Multiple tables can be loaded at a time.

  Updates data in a database in a block mode (one physical write can update multiple rows)

  Uses table-level locks

  Resource consumption: loading at the highest possible throughput

  Duplicate rows allowed

Teradata Parallel Data Pump (TPump)

  Main use: to load or update a small amount of target table rows

  Sends data to a database as a statement which is much slower than using bulk mode

  TPump uses row-level hash locks

  Resource consumption: loading speed can be adjusted using a built-in resource consumption management utility. The throughput can be turned down in peak periods.

  TPump does not support MULTI-SET tables.

Teradata FastLoad example

The following script attached below will load a sample fixed-length columns extract into a Teradata database using FastLoad.

  

SESSIONS 4;

ERRLIMIT 25;

logon tdpid/username,password;

create table gg_cli (

wh_cust_no integer not null,

cust_name varchar(200),

bal_amt decimal(15,3) format �ZZZ,ZZ9.999�

)

unique primary index( wh_cust_no ) ;

SET RECORD UNFORMATTED;

define

                wh_cust_no(char(10)), delim1(char(1)),

                cust_name(char(200)), delim2(char(1)),

                bal_amt(char(18)), delim3(char(1))

                newlinechar(char(1))

file=insert.input;

SHOW;

BEGIN LOADING gg_cli errorfiles error_1, error_2;

insert into gg_cli (

                :wh_cust_no,

                :cust_name,

                :bal_amt

);

END LOADING;

logoff;

Teradata MultiLoad example

The following script attached below will load a sample fixed-length columns extract into a Teradata database using MultiLoad. Use the following command to run load the ggclients.mload file using Teradata FastLoad script:

mload < ggclients.mload

Contents of a ggclients.mload mload script:

.logtable inslogtable;

.logon tdpid/username,password;

create table gg_cli (

wh_cust_no integer not null,

cust_name varchar(200),

bal_amt decimal(15,3) format �ZZZ,ZZ9.999�

)

unique primary index( wh_cust_no ) ;

.BEGIN IMPORT MLOAD tables gg_cli;

.layout ggclilayout;

                .field wh_cust_no 1 char(10);

                .field cust_name 12 char(200);

                .field bal_amt 213 char(18);

.dml label insertclidml;

insert into gg_cli.*;

.import infile insert.input

                format text

                layout ggclilayout

                apply insertclidml;

.END MLOAD;

.logoff;

Teradata TPump example

The sample script attached below loads a sample fixed-length columns extract into a Teradata database using Parallel Data Pump - Teradata TPump.

Contents of a ggclients.tpump script:

.logtable tpumplogtable;

.logon tdpid/username,password;

.BEGIN LOAD SESSION 4;

.layout ggclilayout;

                .field wh_cust_no 1 char(10);

                .field cust_name 12 char(200);

                .field bal_amt 213 char(18);

.dml label insertclidml;

insert into gg_cli.*;

.IMPORT INFILE insert.input

                layout ggclilayout

                apply insertclidml;

.END LOAD;

.logoff;