Re: Collation versioning

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/
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