Re: BUG #18573: Analyze command consumes several GB of memory - more than analyzed table size

Hello,

the table size is 1681 MB. (it was in the bug report, but it has to be
clearer on top of the message).

Kind regards Ales Zeleny

pá 9. 8. 2024 v 6:45 odesílatel Muhammad Waqas <waqas(dot)m(at)bitnine(dot)net> napsal:

> what is the size of table?
>
> 2024년 8월 8일 (목) 오후 1:31, Aleš Zelený <zeleny(dot)ales(at)gmail(dot)com>님이 작성:
>
>> Hello,
>>
>> the default statistics target is:
>>
>> powa=# show default_statistics_target ;
>> default_statistics_target
>> ---------------------------
>> 2500
>> (1 row)
>>
>> So I've changed it to the default:
>> powa=# ALTER TABLE testcase_t3 ALTER COLUMN records SET STATISTICS 100;
>> ALTER TABLE
>>
>> The memory consumption drops down to ~ 1.1GB
>>
>> So you were right, thanks!
>>
>> I thought it was a bug, but possibly it is only a space for an
>> improvement for adding a potential limit for similar cases.
>>
>> Kind regards Ales Zeleny
>>
>> st 7. 8. 2024 v 16:46 odesílatel Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> napsal:
>>
>>> PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
>>> > Is there more I can do to identify why analyze uses that much memory?
>>>
>>> What have you got default_statistics_target set to?
>>>
>>> You might need to decrease the stats target for that composite-array
>>> column. compute_array_stats is fairly aggressive about how much
>>> data it will try to collect, and I can believe that that'd add up
>>> when the array elements are of a wide composite type.
>>>
>>> regards, tom lane
>>>
>>
>
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