About Using Export Without Spool - Teradata Data Mover

Teradata Data Mover User Guide

Product
Teradata Data Mover
Release Number
16.00
Published
December 2016
Language
English (United States)
Last Update
2018-03-29
dita:mapPath
rdo1467305237457.ditamap
dita:ditavalPath
ft:empty
dita:id
B035-4101
lifecycle
previous
Product Category
Analytical Ecosystem

You can preempt spooling preceding a table copy when using Teradata PT API. The Teradata Database writes data to temporary disk space (spool space) where it is held until the select is complete. This action is known as spooling. Although spooling occurs by default to prevent data inconsistencies, it also adds to the time required to copy database objects. To improve performance for a specific table copy in jobs that use Teradata PT API, disable spooling for the table.

Disadvantages of using this feature when copying tables with the Teradata PT API operator include the following:
  • Locks are maintained during the entire copy process.
  • Because the spooling phase detects data conversion errors, eliminating spooling when copying a table can introduce conversion errors. If this happens, correct the errors and restart the job.

The <export_without_spool> element is optional and enabled by default. This element can only be specified in the XML, but not as a parameter on the command-line interface. The element is only available for Teradata PT API jobs, and only applies to Teradata Database 13.10 and later. If you specify true for the value of the <export_without_spool> element in the XML, and the source or target is earlier than Teradata Database 13.10, or if the job uses a different utility, the element is ignored. This element is under the <table> element in the XML file. The following table lists valid values for the <export_without_spool> element.

Value Description
false Data Mover writes to spool space when copying a table.
true Data Mover copies a table without writing to spool space.

This is the default value.

unspecified Equivalent to omitting the <export_without_spool> element in the XML. Data Mover does not use spooling when exporting data from the source Teradata Database in a table copy job that uses the Teradata PT API.
Because you can only disable spooling for a table copy, specify the value true for the <export_without_spool> element under the <table> tag. In the following example, table srcDatabase. Employees is copied, but spooling is disabled for the table.
<database selection="unselected">
	<name>srcDatabase</name>
	<table selection="included">
		<name>Employees</name>
		<export_without_spool>true</export_without_spool>
	</table>
</database>