Override global statement timeout when creating indexes in Postgres#16085
Conversation
| # override the global statement timeout to avoid accidentally squashing | ||
| # a long-running index creation process | ||
| timeout_sql = "SET LOCAL statement_timeout = 0" | ||
| c.execute(timeout_sql) |
There was a problem hiding this comment.
We need to set this back to the default, as we're not in a transaction when creating indices I think?
There was a problem hiding this comment.
Is the autocommit being on the reason that this isn't in a transaction? The statement timeout only applies for a given transaction - if we are not in a transaction then I wonder if it will have any effect. I will do some digging in the docs but they were pretty scarce on information when I looked into this the first time. Do we have any Postgres/psychopg wizards around who might have some arcane insight into this?
There was a problem hiding this comment.
Is the autocommit being on the reason that this isn't in a transaction?
Yes
The statement timeout only applies for a given transaction - if we are not in a transaction then I wonder if it will have any effect.
https://www.postgresql.org/docs/current/sql-set.html says that LOCAL doesn't work outside a transaction, and so we'd need to use SESSION
H-Shay
force-pushed
the
shay/fix_index_timeout
branch
from
3502fea to
c18bc5c
Compare
| # mypy ignore - `statement_timeout` is defined on PostgresEngine | ||
| default_timeout = self.db_pool.engine.statement_timeout # type: ignore[attr-defined] | ||
| undo_timeout_sql = f"SET statement_timeout = {default_timeout}" | ||
| c.execute(undo_timeout_sql) |
There was a problem hiding this comment.
This needs to be in finally section, so if happens even if index creation raises an exception
2 participants
#15853 added a global timeout for long-running Postgres statements, but this may interfere with long-running index creation. This PR adds a local statement timeout to override the global timeout and disable it when creating an index in the background. Fixes #15942.