On Sat, Nov 30, 2024 at 4:15 PM Dmitry Nikitin <pgsql-hack...@dima.nikitin.name> wrote: > > Hello , > > > https://github.com/postgres/postgres/blob/5d39becf8ba0080c98fee4b63575552f6800b012/src/backend/optimizer/prep/prepjointree.c#L3856 > bms_next_member() is allowed to return the zero as a valid value. Subsequent > rt_fetch() offsets that > zero to -1 which leads to the assertion down the code. Nothing wrong here? > Either zero is simply not > possible after that bms_next_member() because of some factors behind the code? >
rtindex 0 is not used, see the logic of setup_simple_rel_arrays and the comments of PlannerInfo.simple_rel_array. /* * simple_rel_array holds pointers to "base rels" and "other rels" (see * comments for RelOptInfo for more info). It is indexed by rangetable * index (so entry 0 is always wasted). Entries can be NULL when an RTE * does not correspond to a base relation, such as a join RTE or an * unreferenced view RTE; or if the RelOptInfo hasn't been made yet. */ > > -- > Best regards, > Dmitry mailto:pgsql-hack...@dima.nikitin.name > > > -- Regards Junwang Zhao
