Re: Optimizing nbtree ScalarArrayOp execution, allowing multi-column ordered scans, skip scan

Hello Peter,

07.04.2024 20:18, Peter Geoghegan wrote:
> On Sun, Apr 7, 2024 at 1:00 PM Alexander Lakhin <exclusion(at)gmail(dot)com> wrote:
>> SELECT * FROM t WHERE a < ANY (ARRAY[1]) AND b < ANY (ARRAY[1]);
>>
>> TRAP: failed Assert("so->numArrayKeys"), File: "nbtutils.c", Line: 560, PID: 3251267
> I immediately see what's up here. WIll fix this in the next short
> while. There is no bug here in builds without assertions, but it's
> probably best to keep the assertion, and to just make sure not to call
> _bt_preprocess_array_keys_final() unless it has real work to do.

Please look at another case, where a similar Assert (but this time in
_bt_preprocess_keys()) is triggered:
CREATE TABLE t (a text, b text);
INSERT INTO t (a, b) SELECT 'a', repeat('b', 100) FROM generate_series(1, 500) g;
CREATE INDEX t_idx ON t USING btree(a);
BEGIN;
DECLARE c CURSOR FOR SELECT a FROM t WHERE a = 'a';
FETCH FROM c;
FETCH RELATIVE 0 FROM c;

TRAP: failed Assert("so->numArrayKeys"), File: "nbtutils.c", Line: 2582, PID: 1130962

Best regards,
Alexander