Re: lock contention on parallel COPY ? - Mailing list pgsql-hackers

From Tom Lane
Subject Re: lock contention on parallel COPY ?
Date
Msg-id 23005.1222452002@sss.pgh.pa.us
Whole thread Raw
In response to Re: lock contention on parallel COPY ?  (Simon Riggs <simon@2ndQuadrant.com>)
Responses Re: lock contention on parallel COPY ?  (Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>)
Re: lock contention on parallel COPY ?  (Simon Riggs <simon@2ndQuadrant.com>)
List pgsql-hackers
Simon Riggs <simon@2ndQuadrant.com> writes:
> Stefan Kaltenbrunner <stefan@kaltenbrunner.cc> writes:
>> samples  %        symbol name
>> 55526    16.5614  LWLockAcquire
>> 29721     8.8647  DoCopy
>> 26581     7.9281  CopyReadLine
>> 25105     7.4879  LWLockRelease
>> 15743     4.6956  PinBuffer
>> 14725     4.3919  heap_formtuple

> Probably loading a table with a generated PK or loading data in
> ascending sequence, so its contending heavily for the rightmost edge of
> the index.

No, given that DoCopy and CopyReadLine are right up there, I think we're
still looking at the COPY phase, not index building.

The profile will probably change completely once index building
starts...
        regards, tom lane


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