Horton

Re: Large expressions in indexes can't be stored (non-TOASTable)

Nathan Bossart <nathandbossart@gmail.com>

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From: Nathan Bossart <nathandbossart@gmail.com>
To: Alexander Lakhin <exclusion@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, "Jonathan S. Katz" <jkatz@postgresql.org>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-09-19T18:36:36Z
Lists: pgsql-hackers

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On Thu, Sep 19, 2024 at 12:00:00PM +0300, Alexander Lakhin wrote:
> I've discovered that Jonathan's initial script:
> CREATE TABLE def (id int);
> SELECT array_agg(n) b FROM generate_series(1,10_000) n \gset
> CREATE OR REPLACE FUNCTION vec_quantizer (a int, b int[]) RETURNS bool
> AS $$ SELECT true $$ LANGUAGE SQL IMMUTABLE;
> CREATE INDEX ON def (vec_quantizer(id, :'b'));
> 
> completed with:
> DROP INDEX CONCURRENTLY def_vec_quantizer_idx;
> 
> triggers an assertion failure:
> TRAP: failed Assert("HaveRegisteredOrActiveSnapshot()"), File: "toast_internals.c", Line: 668, PID: 3723372

Ha, that was fast.  The attached patch seems to fix the assertion failures.
It's probably worth checking if any of the adjacent code paths are
affected, too.

-- 
nathan

Commits

  1. Ensure we have a snapshot when updating various system catalogs.

  2. Remove pg_replication_origin's TOAST table.

  3. Restrict password hash length.

  4. Ensure we have a snapshot when updating pg_index entries.

  5. Add TOAST table to pg_index.

  6. Add toast tables to most system catalogs