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From: jian he <jian.universality@gmail.com>
Date: Sun, 2 Jul 2023 10:38:20 +0800
Message-ID: <CACJufxF-HGe9zLaGaSryeYVq9abz2FyKKtdgghNWktkjnFXOJQ@mail.gmail.com>
Subject: Re: Incremental View Maintenance, take 2
To: Yugo NAGATA <nagata@sraoss.co.jp>
Cc: pgsql-hackers@postgresql.org
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Precedence: bulk

ok. Now I really found a small bug.

this works as intended:
BEGIN;
CREATE INCREMENTAL MATERIALIZED VIEW test_ivm AS SELECT i, MIN(j) as
min_j  FROM mv_base_a group by 1;
INSERT INTO mv_base_a select 1,-2 where false;
rollback;

however the following one:
BEGIN;
CREATE INCREMENTAL MATERIALIZED VIEW test_ivm1 AS SELECT MIN(j) as
min_j  FROM mv_base_a;
INSERT INTO mv_base_a  select 1, -2 where false;
rollback;

will evaluate
tuplestore_tuple_count(new_tuplestores) to 1, it will walk through
IVM_immediate_maintenance function to apply_delta.
but should it be zero?