Horton

Re: Inlining comparators as a performance optimisation

Pavel Stehule <pavel.stehule@gmail.com>

View thread
From: Pavel Stehule <pavel.stehule@gmail.com>
To: Bruce Momjian <bruce@momjian.us>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Robert Haas <robertmhaas@gmail.com>, Peter Geoghegan <peter@2ndquadrant.com>, PG Hackers <pgsql-hackers@postgresql.org>
Date: 2011-12-02T20:04:45Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Speed up conversion of signed integers to C strings.

  2. Remove some unnecessary tests of pgstat_track_counts.

  3. Remove cvs keywords from all files.

  4. Code cleanup for function prototypes: change two K&R-style prototypes

  5. Use Min() instead of min() in qsort, for consistency and to avoid

  6. pgindent run for 8.2.

  7. Switch over to using our own qsort() all the time, as has been proposed

>>
>> [ shrug... ] If you are bothered by that, get off your duff and provide
>> the function for your datatype.  But it's certainly going to be in the
>> noise for btree index usage, and I submit that query parsing/setup
>> involves quite a lot of syscache lookups already.  I think that as a
>> performance objection, the above is nonsensical.  (And I would also
>> comment that your proposal with a handle is going to involve a table
>> search that's at least as expensive as a syscache lookup.)
>
> Agreed.  Doing something once and doing something in the sort loop are
> two different overheads.
>
> I am excited by this major speedup Peter Geoghegan has found.  Postgres
> doesn't have parallel query, which is often used for sorting, so we are
> already behind some of the databases are compared against.  Getting this
> speedup is definitely going to help us.  And I do like the generic
> nature of where we are heading!
>

Oracle has not or had not parallel sort too, and I have a reports so
Oracle does sort faster then PostgreSQL (but without any numbers). So
any solution is welcome

Regards

Pavel