Re: cache lookup failed for collation 0

On 2019-04-11 17:04, Jeevan Chalke wrote:
> The error is coming from get_collation_isdeterministic() when colloid
> passed is 0. I think like we do in get_collation_name(), we should
> return false here when such collation oid does not exist.

I'm not in favor of doing that.  It would risk papering over errors of
omission at other call sites.

The root cause is that the same code match_pattern_prefix() is being
used for text and bytea, but bytea does not use collations, so having
the collation 0 is expected, and we shouldn't call
get_collation_isdeterministic() in that case.

Proposed patch attached.

--
Peter Eisentraut              http://www.2ndQuadrant.com/
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