teradata fastload

Introduction

Fastload is the Teradata utility which can be used to load large amount of data in empty table on a Teradata System.  The property which makes Fastload UNIQUE is its fast speed to load huge amount of data in tables.


You can load data from –

• Disk or Tape drives from the channel attached client system.
• File data on a network attached workstation.
• Any other device which can provide the properly formatted source data

Shoes

Fastload uses multiple sessions and block level operation to load data into table that is why it’s much faster than any other loading utilities.

TIP – However, one Fastload job loads data into one table only. If you want to load data into more than one table , you must submit multiple Fastload jobs—one for each table.

Three requirements for Fastload to execute –

LOG TABLE – This table is used to record all the progress during execution of Fastload. This table exists in the SYSADMIN database under the name of FASTLOG. The structure of the FASTLOG table is as follows –

EMPTY TABLE – Fastload needs the table to be empty before inserting rows into that table. It does not care how this is implemented but it requires empty tables without any prior records. If the table is not empty then Fastload will pause and show the error.

TWO ERROR TABLES – Fastload require two error tables to catch any error which occurs during the execution of the Fastload. It create the error tables itself. Each error tables record error of specific type.

The first error table record any translation or constraint violation error. For e.g. if a row has data which does not match with the data type of its particular column then this row will be captured by error table 1. Insertion of CHAR data in INTEGER data type column.

The second error table captured any error which is related to duplication of values for Unique Primary Indexes (UPI). Fastload will capture only one occurrence of the value and store the duplicate occurrence in the second error table. However if the entire row is duplicated then Fastload count it but does not store the row.

These tables are analyzed later for error handling.

Data Conversion Capabilities


Fastload also allow the data conversion on the column value before inserting it into target table. Following are the conversion allowed by Fastload.

• Numeric-to-numeric (for example integer-to-decimal)
• Character-to-numeric
• Character-to-date
• Date-to-character