Re: Change GUC hashtable to use simplehash?

John Naylor <johncnaylorls@gmail.com>

From: John Naylor <johncnaylorls@gmail.com>
To: Jeff Davis <pgsql@j-davis.com>
Cc: Andres Freund <andres@anarazel.de>, Tom Lane <tgl@sss.pgh.pa.us>, Gurjeet Singh <gurjeet@singh.im>, pgsql-hackers@postgresql.org
Date: 2023-12-18T06:39:02Z
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. Silence warning in older versions of Valgrind

  2. Revert "Speed up tail processing when hashing aligned C strings, take two"

  3. Speed up tail processing when hashing aligned C strings, take two

  4. Teach fasthash_accum to use platform endianness for bytewise loads

  5. Add macro to disable address safety instrumentation

  6. Convert uses of hash_string_pointer to fasthash equivalent

  7. Speed up tail processing when hashing aligned C strings

  8. Add helper functions for dshash tables with string keys.

  9. Fix warnings in cpluspluscheck

  10. Further cosmetic review of hashfn_unstable.h

  11. Simplify initialization of incremental hash state

  12. Add optimized C string hashing

  13. Add inline incremental hash functions for in-memory use

  14. Make all Perl warnings fatal

Attachments

I wrote:
> Updated next steps:

> * Add some desperately needed explanatory comments.

There is a draft of this in v10-0001. I also removed the validation
scaffolding and ran pgindent. This could use some review and/or
bikeshedding, in particular on the name hashfn_unstable.h. I also
considered *_volatile.h or *_inmemory.h, but nothing stands out as
more clear.

> * Use this in some existing cases where it makes sense.

For now just two:
v10-0002 is Jeff's change to the search path cache, but with the
chunked interface that I found to be faster.
v10-0003 is a copy of something buried in an earlier version: use in
pgstat. Looks nicer, but not yet tested.