Horton

Re: add function for creating/attaching hash table in DSM registry

Rahila Syed <rahilasyed90@gmail.com>

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From: Rahila Syed <rahilasyed90@gmail.com>
To: Florents Tselai <florents.tselai@gmail.com>
Cc: Nathan Bossart <nathandbossart@gmail.com>, Sami Imseih <samimseih@gmail.com>, Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>, pgsql-hackers@postgresql.org
Date: 2025-06-11T13:45:56Z
Lists: pgsql-hackers 
Hi,

Thank you for proposing this enhancement to the DSM registry. It will make
it easier
to use dshash functionality.


> While trying to port some existing DSMR code, I came across this
> limitation:
>
> How can one dsa_allocate in the same area as the returned dshash_table ?
> in other words: shouldn't the state->dsa_handle be returned somehow ?
>
>
+1. FWIW, Having used the DSA apis in my code, I think having the registry
return
the mapped dsa address or dsa handle will benefit users who use dsa_allocate
to allocate smaller chunks within the dsa.

Commits

  1. Fix cross-version upgrade test breakage from commit fe07100e82.

  2. Add GetNamedDSA() and GetNamedDSHash().

  3. Remove dynamic_shared_memory_type=none

  4. Introduce dynamic shared memory areas.

  5. Relax the requirement that all lwlocks be stored in a single array.