Re: Explain analyze gives no info

Richard Huxton <dev(at)archonet(dot)com> writes:
> Relyea, Mike wrote:
>> Any suggestions for how to get the explain analyze output?

> You should get *some* output. Unfortunately, I don't think it will show
> you anything useful. The effort is almost certainly all going on the
> FK's and you can't see through the trigger code to see what's happening
> there.

Yeah. CVS-tip EXPLAIN ANALYZE will at least tell you how much time was
chewed by each trigger, but it still sees each trigger as a black box.

However, I don't think we need to guess very hard about what's going on
here. Obviously, one of the ON DELETE foreign key triggers is scanning
the referencing table with a seqscan, which probably means that either
there's no index at all on the referencing column, or the referencing
column is of a different datatype than the master. Look through the
tables that reference this one and check the indexes and datatypes.

regards, tom lane