DROP INDEX

Function

DROP INDEX deletes an index.

Precautions

Only the owner of an index or a system administrator can run DROP INDEX command.

Syntax

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DROP INDEX [ CONCURRENTLY ][ IF EXISTS ] 
    index_name [, ...] [ CASCADE | RESTRICT ];

Parameters

• CONCURRENTLY

  Deletes an index without locking concurrent selections, inserts, updates, and deletes on the index table. A normal DROP INDEX obtains an exclusive lock on the table to prevent other access until the index is deleted. With this option, the command waits until the conflicting transaction is complete.

  Note that only one index name can be specified and the CASCADE option is not supported. (Therefore, indexes that support UNIQUE or PRIMARY KEY constraints cannot be deleted in this way.) Regular DROP INDEX commands can be executed within a transaction block, but cannot be executed in DROP INDEX CONCURRENTLY mode.

• IF EXISTS

  Sends a notice instead of an error if the specified index does not exist.

• index_name

  Specifies the name of the index to be deleted.

  Value range: An existing index.

• CASCADE | RESTRICT
  • CASCADE: automatically deletes all objects that depend on the index to be deleted.
  • RESTRICT (default): refuses to delete the index if any objects depend on it.

Examples

Delete the ds_ship_mode_t1_index2 index:

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DROP INDEX tpcds.ds_ship_mode_t1_index2;

Helpful Links

ALTER INDEX, CREATE INDEX