On Thu, 2024-02-29 at 12:07 +0100, Dominique Devienne wrote:
> But I'm sure indexes on columns "not used at all in a statement" are eliminated early and easily/cheaply,
> w/o even getting into more complex consideration like statistics and co. Aren't they?
You may want a "SELECT count(*) FROM tab" to consider an index-only
scan on a small index, right? I'm not saying that it is a large
overhead, but if you actually have dozens of indexes, it can
make processing slower.
Yours,
Laurenz Albe