pythonpostgresqlsqlalchemypsycopg2vacuum

Is it possible to issue a "VACUUM ANALYZE <tablename>" from psycopg2 or sqlalchemy for PostgreSQL?


Well, the question pretty much summarises it. My db activity is very update intensive, and I want to programmatically issue a Vacuum Analyze. However I get an error that says that the query cannot be executed within a transaction. Is there some other way to do it?


Solution

  • This is a flaw in the Python DB-API: it starts a transaction for you. It shouldn't do that; whether and when to start a transaction should be up to the programmer. Low-level, core APIs like this shouldn't babysit the developer and do things like starting transactions behind our backs. We're big boys--we can start transactions ourself, thanks.

    With psycopg2, you can disable this unfortunate behavior with an API extension: run connection.autocommit = True. There's no standard API for this, unfortunately, so you have to depend on nonstandard extensions to issue commands that must be executed outside of a transaction.

    No language is without its warts, and this is one of Python's. I've been bitten by this before too.