Alvaro Melo <al_nunes@atua.com.br> writes:
> I have a peculiar situation here. I'm optimizing some queries and I
> noticed that EXPLAIN doesn't always show the tables involved in the
> query. Below is a little example, but I have other examples with longer
> queries. Note that the tables tabela_documento_fiscal and pessoa aren't
> considered on it's output. Am I missing someting or it might be a bug?
It looks to me like it's optimizing away the left joins, presumably
on the grounds that they join to a unique key so there can't be more
than one matching row --- and this query has no need to know exactly
which row, if any, matches.
regards, tom lane
