Horton

Re: reducing the footprint of ScanKeyword (was Re: Large writable variables)

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: David Fetter <david@fetter.org>
Cc: Robert Haas <robertmhaas@gmail.com>, Andres Freund <andres@anarazel.de>, Andrew Gierth <andrew@tao11.riddles.org.uk>, John Naylor <jcnaylor@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2018-12-26T17:07:36Z
Lists: pgsql-hackers 
David Fetter <david@fetter.org> writes:
> On Wed, Dec 26, 2018 at 11:22:39AM -0500, Tom Lane wrote:
>> In my hands, the only part of the low-level parsing code that
>> commonly shows up as interesting in profiles is the Bison engine.

> Should we be considering others?

We've looked around before, IIRC, and not really seen any arguably
better tools.

			regards, tom lane

Commits

  1. Use perfect hashing, instead of binary search, for keyword lookup.

  2. Reduce the size of the fmgr_builtin_oid_index[] array.

  3. Replace the data structure used for keyword lookup.