How to delete all rows in a PostgreSQL table?
Tip: TRUNCATE is a PostgreSQL extension that provides a faster mechanism to remove all rows from a table. There are two ways to delete rows in a table using information contained in other tables in the database: using sub-selects, or specifying additional tables in the USING clause.
How long does delete query take in PostgreSQL?
We are running a very simple delete query on it which takes 45 minutes to complete: 1- Added an index on timestamp column, which did not help. 2- Removed the rows in batches of 20 or 50 using a function, which was still awfully slow.
What happens if the where clause is absent in PostgreSQL?
If the WHERE clause is absent, the effect is to delete all rows in the table. The result is a valid, but empty table. Tip: TRUNCATE is a PostgreSQL extension that provides a faster mechanism to remove all rows from a table.
Do you have to have select privilege in PostgreSQL?
The syntax of the RETURNING list is identical to that of the output list of SELECT. You must have the DELETE privilege on the table to delete from it, as well as the SELECT privilege for any table in the USING clause or whose values are read in the condition.
Tip: TRUNCATE is a PostgreSQL extension that provides a faster mechanism to remove all rows from a table. By default, DELETE will delete rows in the specified table and all its child tables. If you wish to delete only from the specific table mentioned, you must use the ONLY clause.
How to automatically delete old records in PostgreSQL?
You could run a daily (you decide) cron-job to schedule simple DELETE commands or use pgAgent for the purpose. Or you could use partitioning with weekly partitions. That makes deleting very cheap: just keep the latest two weeks and drop older partitions. Before Postgres 10, partitioning was always based on inheritance.
If the WHERE clause is absent, the effect is to delete all rows in the table. The result is a valid, but empty table. Tip: TRUNCATE is a PostgreSQL extension that provides a faster mechanism to remove all rows from a table.
How to do automatic aging out in PostgreSQL?
Create a RULE or a TRIGGER on the master table that redirects INSERTs to the partition of the current week based on system time. Either way, you can always log to the master table log. Create partitions ahead of time. Make that several weeks ahead to be sure and run a weekly cron job that adds future child tables