On Mon, 4 Dec 2023 at 02:54, Laurenz Albe <laurenz.a...@cybertec.at> wrote:
> REINDEX is philosophically a maintenance command and a Postgres > > extension not in the SQL standard, so it does not really qualify as a > > DDL because it does not do in object definitions, so we could just > > delete this comment. Or could it be more useful to consider that as a > > special case and report it as a DDL, impacting log_statements? > > It should be qualified just like CREATE INDEX. > Both are not covered by the standard, which does not mention indexes, > since they are an "implementation detail". > > I think that it is pretty clear that CREATE INDEX should be considered > DDL, since it defines (creates) and object. The same should apply to > REINDEX. > Isn't REINDEX more like REFRESH MATERIALIZED VIEW and CLUSTER (especially without USING)? CREATE INDEX (really, CREATE anything) is clearly DDL as it creates a new object, and DROP and ALTER are the same. But REINDEX just reaches below the abstraction and maintains the existing object without changing its definition. I don't think whether it's in the standard is the controlling fact. It's not just DDL vs. not; there are naturally at least 3 categories: DDL, maintenance, and data modification. Getting back to the question at hand, I think REINDEX should be treated the same as VACUUM and CLUSTER (without USING). So if and only if they are considered DDL for this purpose then REINDEX should be too.
