Re: Performance die when COPYing to table with bigint PK

Quite possible.
But anyway - I don't think performance degradation must be so huge in
case of using UNIQUE indexes.

On Mon, Aug 1, 2011 at 12:06 PM, Vitalii Tymchyshyn <tivv00(at)gmail(dot)com> wrote:
> 31.07.11 16:51, Robert Ayrapetyan написав(ла):
>>
>> Hello.
>>
>> I've found strange behavior of my pg installation (tested both 8.4 and
>> 9.0 - they behave same) on FreeBSD platform.
>> In short - when some table have PK on bigint field - COPY to that
>> table from file becomes slower and slower as table grows. When table
>> reaches ~5GB - COPY of 100k records may take up to 20 mins. I've
>> experimented with all params in configs, moved indexes to separate hdd
>> etc - nothing made any improvement. However, once I'm dropping 64 bit
>> PK - COPY of 100k records passes in seconds. Interesting thing - same
>> table has other indexes, including composite ones, but none of them
>> include bigint fields, that's why I reached decision that bug
>> connected with indexes on bigint fields only.
>
> I did see this behavior, but as for me it occurs for UNIQUE indexes only
> (including PK), not dependent on field type.
> You can check this by dropping PK and creating it as a regular non-unique
> index.
>
> Best regards, Vitalii Tymchyshyn
>

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Ayrapetyan Robert,
Comodo Anti-Malware Data Processing Analysis and Management System (CAMDPAMS)
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