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

From Stefan Kaltenbrunner
Subject Re: lock contention on parallel COPY ?
Date
Msg-id 48DD24FE.5050909@kaltenbrunner.cc
Whole thread Raw
In response to Re: lock contention on parallel COPY ?  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: lock contention on parallel COPY ?  (Simon Riggs <simon@2ndQuadrant.com>)
List pgsql-hackers
Tom Lane wrote:
> 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...

yeah this profile is only showing the COPY phase ...

Stefan


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