EXPLAIN on DELETE statements

Started by Janning Vygenover 21 years ago2 messagesgeneral
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#1Janning Vygen
vygen@gmx.de

Hi,

EXPLAIN on delete stamements works, but doesn't show me all the subsequent
deletes or checks which has to be done because of foreign keys
cascading/restricting.

Is there a solution to show up which tables are checked and which scans the
planner is going to use to check these related tables?

kind regards,
janning

#2Grant McLean
grant@catalyst.net.nz
In reply to: Janning Vygen (#1)
Re: EXPLAIN on DELETE statements

On Wed, 2004-07-28 at 23:41, Janning Vygen wrote:

Hi,

EXPLAIN on delete stamements works, but doesn't show me all the subsequent
deletes or checks which has to be done because of foreign keys
cascading/restricting.

Is there a solution to show up which tables are checked and which scans the
planner is going to use to check these related tables?

You could try enabling the 'log_statement' and related entries in the
postgresql.conf file and possibly the -d option for debugging on the
Postmaster. I know I get the referential integrity check queries
showing up in the PostgreSQL log (syslog actually) on my server but I'm
not exactly sure what I did to cause that :-). Here's an example:

LOG: statement: SELECT 1 FROM ONLY "public"."audit_type" x WHERE
"audit_type_id" = $1 FOR UPDATE OF x

Regards
Grant