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When to use truncate or drop table in redshift?
For example, if you have 2 shells open with redshift shell, you will not be able to drop a table from the first shell, that participate in an open transaction in the second shell. After I committed / rolled back in the second window, truncate worked perfectly. Hope it helped.
How to roll back truncate in Amazon Redshift?
Use the TRUNCATE command to delete all of the rows from the CATEGORY table: Attempt to roll back a TRUNCATE operation: The DATE table remains empty after the ROLLBACK command because the TRUNCATE command committed automatically. © 2021, Amazon Web Services, Inc. or its affiliates.
Why does Amazon Redshift use table level locks?
Amazon Redshift uses table-level locks. You might experience locking conflicts if you perform frequent DDL operations on user tables, such as ALTER, DROP or TRUNCATE, or DML changes such as UPDATE, DELETE, or INSERT.
Why are some queries blocked in Amazon Redshift?
Other queries or transactions that are waiting to acquire the same lock are blocked. For more information about why a query might hang, see Query hangs. To solve a locking problem, identify the session (PID) that is holding the lock and then terminate the session. If the session doesn’t terminate, reboot your cluster.
How to drop a table in AWS Redshift?
Only the owner of the table, the schema owner, a superuser, or a user or group assigned the DROP privilege can drop a table. If you are trying to empty a table of rows, without removing the table, use the DELETE or TRUNCATE command. DROP TABLE removes constraints that exist on the target table.
How to find column names in redshift tables?
The below query allows us to find a column from all of the tables and schemas in Redshift. Simply edit the c.column_name like value and it returns a list of all the tables with a column that agrees with this condition.
What does redshift show on a feedback table?
If a table contains columns that are referenced by views or other tables, Amazon Redshift displays a message such as the following. The following command set creates a FEEDBACK table and a BUYERS table and then drops both tables with a single command: