Horton

Re: Large writable variables

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

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: Robert Haas <robertmhaas@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>, Thomas Munro <thomas.munro@enterprisedb.com>
Date: 2018-10-16T23:48:42Z
Lists: pgsql-hackers 
BTW, I looked around for .o files with large BSS numbers, and came across

$ size src/interfaces/ecpg/ecpglib/prepare.o
   text    data     bss     dec     hex filename
   4023       4 1048576 1052603  100fbb src/interfaces/ecpg/ecpglib/prepare.o

That megabyte is from a statically allocated statement cache array.
Seems a bit unfriendly to users of ecpglib, given that many apps
would never use the statement cache (AFAICT you have to explicitly
ask for auto-prepare mode to get to that code).

Doesn't look hard to fix though.

			regards, tom lane

Commits

  1. Apply unconstify() in more places

  2. Improve unconstify() documentation

  3. Drop const cast from dlsym() calls

  4. Const-ify a few more large static tables.

  5. Improve tzparse's handling of TZDEFRULES ("posixrules") zone data.

  6. Avoid statically allocating statement cache in ecpglib/prepare.c.

  7. Reorder FmgrBuiltin members, saving 25% in size.

  8. Add macro to cast away const without allowing changes to underlying type.

  9. Mark constantly allocated dest receiver as const.

  10. Avoid statically allocating formatting.c's format string caches.

  11. Correct constness of system attributes in heap.c & prerequisites.

  12. Avoid statically allocating gmtsub()'s timezone workspace.

  13. Correct constness of a few variables.

  14. Move the replication lag tracker into heap memory.