15.00 - Considerations For Dropping Hash Indexes to Enable Client Batch Load Utilities - Teradata Database

Teradata Database SQL Data Definition Language Detailed Topics

Product
Teradata Database
Release Number
15.00
Content Type
Programming Reference
Publication ID
B035-1184-015K
Language
English (United States)

Considerations For Dropping Hash Indexes to Enable Client Batch Load Utilities

You cannot drop a hash index to enable batch data loading by utilities such as MultiLoad and FastLoad as long as queries are running that access that hash index. Each such query places a READ lock on the hash index while it is running, so it blocks the completion of any DROP HASH INDEX transaction until the READ lock is removed. Furthermore, as long as a DROP HASH INDEX transaction is running, batch data loading jobs against the underlying table of the hash index cannot begin processing because of the EXCLUSIVE lock DROP HASH INDEX places on the base table that defines the index.