Horton

Pg17 Crash in Planning (Arrays + Casting + UDF)

Paul Ramsey <pramsey@cleverelephant.ca>

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From: Paul Ramsey <pramsey@cleverelephant.ca>
To: Pgsql Hackers <pgsql-hackers@postgresql.org>
Cc: Regina Obe <lr@pcorp.us>, Fredrik Widlert <fredrik.widlert@digpro.se>
Date: 2024-10-09T18:52:25Z
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. Avoid crash in estimate_array_length with null root pointer.

  2. Teach estimate_array_length() to use statistics where available.

Hackers,

This extremely odd case [2] came in via a report using a lot of PostGIS functions, but it can be reconfigured into a pure-PostgreSQL crasher [1].

CREATE TABLE n (i integer);

CREATE OR REPLACE FUNCTION add(integer)
    RETURNS integer
    AS 'SELECT 2 * $1 + 4 * $1'
    LANGUAGE 'sql' IMMUTABLE STRICT PARALLEL SAFE;

SELECT add(array_length(array_agg(i)::numeric[],1)::integer) FROM n;

The stack trace shows it doesn’t get past planning, and in fact it doesn’t care if the table has data in it or not.

ATB,

P


[1] https://trac.osgeo.org/postgis/ticket/5793#comment:8
[2] https://lists.osgeo.org/pipermail/postgis-devel/2024-October/030428.html