Horton

Re: Collation versioning

Peter Eisentraut <peter.eisentraut@2ndquadrant.com>

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From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
To: Michael Paquier <michael@paquier.xyz>, Thomas Munro <thomas.munro@gmail.com>
Cc: Julien Rouhaud <rjuju123@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Laurenz Albe <laurenz.albe@cybertec.at>, Douglas Doole <dougdoole@gmail.com>, Christoph Berg <myon@debian.org>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2020-07-09T08:00:55Z
Lists: pgsql-hackers 
On 2020-07-08 08:26, Michael Paquier wrote:
> On Wed, Jul 08, 2020 at 06:12:51PM +1200, Thomas Munro wrote:
>> I still wish I had a better idea than this:
>>
>> +/*
>> + * Returns whether the given index access method depend on a stable collation
>> + * order.
>> + */
>> +static bool
>> +index_depends_stable_coll_order(Oid amoid)
>> +{
>> +       return (amoid != HASH_AM_OID &&
>> +                       strcmp(get_am_name(amoid), "bloom") != 0);
>> +}
>>
>> I'm doing some more testing and looking for weird cases...  More soon.
> 
> Wouldn't the normal way to track that a new field in IndexAmRoutine?
> What you have here is not extensible.

Yeah, this should be decided and communicated by the index AM somehow.

Perhaps it would also make sense to let the index AM handle the 
differences between deterministic and nondeterministic collations.  I 
don't know how the bloom AM works, though, to determine whether that 
makes sense.

In order not to derail this patch set I think it would be okay for now 
to just include all index AMs in dependency tracking and invent a 
mechanism later that excludes hash and bloom in an extensible manner.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Doc: Document known problem with Windows collation versions.

  2. Add collation versions for FreeBSD.

  3. Tolerate version lookup failure for old style Windows locale names.

  4. Track collation versions for indexes.

  5. Add pg_depend.refobjversion.

  6. Remove pg_collation.collversion.

  7. Fix the MSVC build for versions 2015 and later.

  8. Add collation versions for Windows.

  9. Implement type regcollation

  10. Use libc version as a collation version on glibc systems.

  11. Make type "name" collation-aware.