15.00 - DROP HASH INDEX - Teradata Database

Teradata Database SQL Data Definition Language Detailed Topics

prodname
Teradata Database
vrm_release
15.00
category
Programming Reference
featnum
B035-1184-015K

DROP HASH INDEX

Restrictions on Dropping a Hash Index on a Table Concurrent With Dynamic AMP Sample Emulation on That Table

You cannot drop a hash index for a table while that table is subject to dynamic AMP sample emulation. Otherwise, the system returns an error.

To disable dynamic AMP sampling, use the DIAGNOSTIC HELP SAMPLES statement (see “DIAGNOSTIC HELP SAMPLES” in SQL Data Manipulation Language) to determine which samples have been set, then use the DIAGNOSTIC SET SAMPLES statement (see “DIAGNOSTIC SET SAMPLES” in SQL Data Manipulation Language) to disable them.

If you want to use dynamic AMP sampling on the table from which you dropped the hash index, you must use the following general procedure:

1 Drop the hash index from the table on the target system.

2 Extract a fresh dynamic AMP sample from the target system.

3 Apply the fresh sample to the source system.