Restrictions on Dropping a Join Index on a Table Concurrent with Dynamic AMP Sample Emulation on that Table
You cannot drop a join index for a table while that table is subject to dynamic AMP sample emulation. To disable dynamic AMP sampling, contact Teradata Support.
To use dynamic AMP sampling on the table from which you dropped the join index, use the following general procedure:
- Drop the join index from the table on the target system.
- Extract a fresh dynamic AMP sample from the target system.
- Apply the fresh sample to the source system.
Considerations for Dropping Join Indexes to Enable Client Batch Load Utilities
You cannot drop a join index to enable batch data loading by utilities such as MultiLoad and FastLoad if running queries access that index. Each such query places a READ lock on the join index while it is running, blocking the completion of DROP JOIN INDEX until the READ lock is removed. If a DROP JOIN INDEX transaction is running, batch data loading jobs against the underlying tables of the join index cannot begin processing, because of the EXCLUSIVE lock DROP JOIN INDEX places on the base table set of the index.