Re: Getting following error in using cursor to fetch the records from a large table in c language

M Tarkeshwar Rao wrote:
> When we running with vacuum full we are getting following error message.
>
> Error:
> -------
> user was holding a relation lock for too long
>
> Any idea about this error.

That means that you got a replication conflict, which is to be expected,
because VACUUM (FULL) is also one of the commands that require an
ACCESS EXCLUSIVE lock.

First suggestion: don't use VACUUM (FULL).

Second suggestion: A standby server can *either* be used for high
availability, in which case queries on the standby should be forbidden
or canceled in case of conflicts, *or* it can be used to run resource
intensive reading queries, in which case application of the transaction
log should be delayed.

Don't try to use a standby for both - use two standby servers.

Yours,
Laurenz Albe
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