Re: Vacuum statistics

Hi!

On 29.10.2024 14:02, Alena Rybakina wrote:
> On 28.10.2024 16:40, Alexander Korotkov wrote:
>> On Sun, Aug 25, 2024 at 6:59 PM Alena Rybakina
>> <a.rybakina@postgrespro.ru>  wrote:
>>> I didn't understand correctly - did you mean that we don't need SRF if
>>> we need to display statistics for a specific object?
>>>
>>> Otherwise, we need this when we display information on all database
>>> objects (tables or indexes):
>>>
>>> while ((entry = ScanStatSnapshot(pgStatLocal.snapshot.stats, &hashiter))
>>> != NULL)
>>> {
>>>       CHECK_FOR_INTERRUPTS();
>>>
>>>       tabentry = (PgStat_StatTabEntry *) entry->data;
>>>
>>>       if (tabentry != NULL && tabentry->vacuum_ext.type == type)
>>>           tuplestore_put_for_relation(relid, rsinfo, tabentry);
>>> }
>>>
>>> I know we can construct a HeapTuple object containing a TupleDesc,
>>> values, and nulls for a particular object, but I'm not sure we can
>>> augment it while looping through multiple objects.
>>>
>>> /* Initialise attributes information in the tuple descriptor */
>>>
>>>    tupdesc = CreateTemplateTupleDesc(PG_STAT_GET_SUBSCRIPTION_STATS_COLS);
>>>
>>> ...
>>>
>>> PG_RETURN_DATUM(HeapTupleGetDatum(heap_form_tuple(tupdesc, values, nulls)));
>>>
>>>
>>> If I missed something or misunderstood, can you explain in more detail?
>> Actually, I mean why do we need a possibility to return statistics for
>> all tables/indexes in one function call?  User anyway is supposed to
>> use pg_stat_vacuum_indexes/pg_stat_vacuum_tables view, which do
>> function calls one per relation.  I suppose we can get rid of
>> possibility to get all the objects in one function call and just
>> return a tuple from the functions like other pgstatfuncs.c functions
>> do.
>>
> I haven’t thought about this before and agree with you. Thanks for the 
> clarification! I'll fix the patch this evening and release the updated 
> version.

I updated the patches as per your suggestion. You can see it here [0].

[0] 
https://www.postgresql.org/message-id/85b963fe-5977-43aa-9241-75b862abcc69%40postgrespro.ru