Chris
Mark Lewis wrote:
Tom,
I've got a similar problem with deletes taking a very long time. I know that there are lots of foreign keys referencing this table, and other foreign keys referencing those tables, etc. I've been curious, is there a way to find out how long the foreign key checks take for each dependent table?
-- Mark Lewis
On Thu, 2005-03-24 at 16:52, Tom Lane wrote:
Karim Nassar <[EMAIL PROTECTED]> writes:
Here is the statement:
orfs=# explain analyze DELETE FROM int_sensor_meas_type WHERE
id_meas_type IN (SELECT * FROM meas_type_ids);
QUERY PLAN -----------------------------------------------------------------------------------------------------------------------------
Hash Join (cost=11.53..42.06 rows=200 width=6) (actual
time=1.564..2.840 rows=552 loops=1)
...
Total runtime: 2499616.216 ms
(7 rows)
Notice that the actual join is taking 2.8 ms. The other ~40 minutes is in operations that we cannot see in this plan, but we can surmise are ON DELETE triggers.
Where do I go from here?
Look at what your triggers are doing. My private bet is that you have unindexed foreign keys referencing this table, and so each deletion forces a seqscan of some other, evidently very large, table(s).
regards, tom lane
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