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

SQL Data Definition Language Detailed Topics

Deployment
VantageCloud
VantageCore
Edition
Enterprise
IntelliFlex
VMware
Product
Analytics Database
Teradata Vantage
Release Number
17.20
Published
June 2022
Language
English (United States)
Last Update
2023-07-11
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B035-1184
lifecycle
latest
Product Category
Teradata Vantage™

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.