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Amazon Redshift
Database Developer Guide (API Version 2012-12-01)

STV_LOCKS

Use the STV_LOCKS table to view any current updates on tables in the database.

Amazon Redshift locks tables to prevent two users from updating the same table at the same time. While the STV_LOCKS table shows all current table updates, query the STL_TR_CONFLICT table to see a log of lock conflicts. Use the SVV_TRANSACTIONS view to identify open transactions and lock contention issues.

STV_LOCKS is visible only to superusers. For more information, see Visibility of Data in System Tables and Views.

Table Columns

Column Name Data Type Description
table_id bigint Table ID for the table acquiring the lock.
last_commit timestamp Timestamp for the last commit in the table.
last_update timestamp Timestamp for the last update for the table.
lock_owner bigint Transaction ID associated with the lock.
lock_owner_pid bigint Process ID associated with the lock.
lock_owner_start_ts timestamp Timestamp for the transaction start time.
lock_owner_end_ts timestamp Timestamp for the transaction end time.
lock_status character (22) Status of the process either waiting for or holding a lock.

Sample Query

To view all locks taking place in current transactions, type the following command:

Copy
select table_id, last_update, lock_owner, lock_owner_pid from stv_locks;

This query returns the following sample output, which displays three locks currently in effect:

Copy
table_id | last_update | lock_owner | lock_owner_pid ----------+----------------------------+------------+---------------- 100004 | 2008-12-23 10:08:48.882319 | 1043 | 5656 100003 | 2008-12-23 10:08:48.779543 | 1043 | 5656 100140 | 2008-12-23 10:08:48.021576 | 1043 | 5656 (3 rows)

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