Re: Drop or alter column under load give ERROR #42804 structure of query does not match function result type: - Mailing list pgsql-general

Victor Blomqvist wrote:
[race condition causes errors due to stale plans immediately after ALTER TABLE DROP]
> Note that these errors most of the time only happens very briefly at the same time as the ALTER is
> run. When I did some experiments today the server in total had around 3k req/s with maybe 0.1% of them
> touching the table being updated, and the error then happens maybe 1-10% of the times I try this
> operation. If I do the operation on a table with more load the error will happen more frequently.

As far as I gleaned from reading the source, plan cache invalidation happens by signals
sent to the other backends, so I can see why there can be small delays.
I wonder if there is any good way to improve this.

Yours,
Laurenz Albe