[PERFORM] Poor performance when deleting from entity-attribute-value type master-table
Hi all. Using PG-9.4.0 I'm seeing this trying to delete from an entity-master table: *# explain analyze delete from onp_crm_entity where entity_id IN (select tmp.delivery_id from temp_delete_delivery_id tmp); QUERY PLAN --- Delete on onp_crm_entity (cost=0.43..5673.40 rows=1770 width=12) (actual time=7.370..7.370 rows=0 loops=1) - Nested Loop (cost=0.43..5673.40 rows=1770 width=12) (actual time=0.050..1.374 rows=108 loops=1) - Seq Scan on temp_delete_delivery_id tmp (cost=0.00..27.70 rows=1770 width=14) (actual time=0.014..0.080 rows=108 loops=1) - Index Scan using onp_crm_entity_pkey on onp_crm_entity (cost=0.43..3.18 rows=1 width=14) (actual time=0.010..0.011 rows=1 loops=108) Index Cond: (entity_id = tmp.delivery_id) Planning time: 0.314 ms Trigger for constraint onp_crm_activity_entity_id_fkey: time=4.141 calls=108 Trigger for constraint ... Trigger for constraint ... Trigger for constraint ... I have lots of tables referencing onp_crm_entity(entity_id) so I expect the poor performance of deleting from it is caused by all the triggers firing to check FKI-constraints. Are there any ways around this or do people simply avoid having FKs in schemas like this? Thanks. -- Andreas Joseph Krogh CTO / Partner - Visena AS Mobile: +47 909 56 963 andr...@visena.com mailto:andr...@visena.com www.visena.com https://www.visena.com https://www.visena.com
Re: [PERFORM] Poor performance when deleting from entity-attribute-value type master-table
Andreas Joseph Krogh andr...@visena.com writes: Hi all. Using PG-9.4.0 I'm seeing this trying to delete from an entity-master table: *# explain analyze delete from onp_crm_entity where entity_id IN (select tmp.delivery_id from temp_delete_delivery_id tmp); QUERY PLAN --- Delete on onp_crm_entity (cost=0.43..5673.40 rows=1770 width=12) (actual time=7.370..7.370 rows=0 loops=1) - Nested Loop (cost=0.43..5673.40 rows=1770 width=12) (actual time=0.050..1.374 rows=108 loops=1) - Seq Scan on temp_delete_delivery_id tmp (cost=0.00..27.70 rows=1770 width=14) (actual time=0.014..0.080 rows=108 loops=1) - Index Scan using onp_crm_entity_pkey on onp_crm_entity (cost=0.43..3.18 rows=1 width=14) (actual time=0.010..0.011 rows=1 loops=108) Index Cond: (entity_id = tmp.delivery_id) Planning time: 0.314 ms Trigger for constraint onp_crm_activity_entity_id_fkey: time=4.141 calls=108 Trigger for constraint ... Trigger for constraint ... Trigger for constraint ... I have lots of tables referencing onp_crm_entity(entity_id) so I expect the poor performance of deleting from it is caused by all the triggers firing to check FKI-constraints. Are there any ways around this or do people simply avoid having FKs in schemas like this? The classic problem is that one/more of your referring tables is non-trivial in size and you are missing an index on the referring column(s). Insure that this condition does not exist before butchering your design :-) Thanks. -- Andreas Joseph Krogh CTO / Partner - Visena AS Mobile: +47 909 56 963 andr...@visena.com www.visena.com [cid] -- Jerry Sievers Postgres DBA/Development Consulting e: postgres.consult...@comcast.net p: 312.241.7800 -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Poor performance when deleting from entity-attribute-value type master-table
På mandag 09. februar 2015 kl. 22:36:55, skrev Igor Neyman iney...@perceptron.com mailto:iney...@perceptron.com: From: pgsql-performance-ow...@postgresql.org [mailto:pgsql-performance-ow...@postgresql.org]On Behalf Of Andreas Joseph Krogh Sent: Monday, February 09, 2015 4:13 PM To: pgsql-performance@postgresql.org Subject: [PERFORM] Poor performance when deleting from entity-attribute-value type master-table Hi all. Using PG-9.4.0 I'm seeing this trying to delete from an entity-master table: *# explain analyze delete from onp_crm_entity where entity_id IN (select tmp.delivery_id from temp_delete_delivery_id tmp); QUERY PLAN --- Delete on onp_crm_entity (cost=0.43..5673.40 rows=1770 width=12) (actual time=7.370..7.370 rows=0 loops=1) - Nested Loop (cost=0.43..5673.40 rows=1770 width=12) (actual time=0.050..1.374 rows=108 loops=1) - Seq Scan on temp_delete_delivery_id tmp (cost=0.00..27.70 rows=1770 width=14) (actual time=0.014..0.080 rows=108 loops=1) - Index Scan using onp_crm_entity_pkey on onp_crm_entity (cost=0.43..3.18 rows=1 width=14) (actual time=0.010..0.011 rows=1 loops=108) Index Cond: (entity_id = tmp.delivery_id) Planning time: 0.314 ms Trigger for constraint onp_crm_activity_entity_id_fkey: time=4.141 calls=108 Trigger for constraint ... Trigger for constraint ... Trigger for constraint ... I have lots of tables referencing onp_crm_entity(entity_id) so I expect the poor performance of deleting from it is caused by all the triggers firing to check FKI-constraints. Andreas, do you have indexes on FK columns in child tables? If not – there is your problem. Yes, they have indexes, but deleting 1M rows still results in calling the triggers 1M times * number of FKs... -- Andreas Joseph Krogh CTO / Partner - Visena AS Mobile: +47 909 56 963 andr...@visena.com mailto:andr...@visena.com www.visena.com https://www.visena.com https://www.visena.com
Re: [PERFORM] Poor performance when deleting from entity-attribute-value type master-table
On 02/09/2015 01:12 PM, Andreas Joseph Krogh wrote: Are there any ways around this or do people simply avoid having FKs in schemas like this? Don't use EAV. It's a bad design pattern, especially for you, and you've just discovered one of the reasons why. (In fact, I am just today dismantling an EAV database and normalizing it, and so far application throughput is up 500%) -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Poor performance when deleting from entity-attribute-value type master-table
From: pgsql-performance-ow...@postgresql.org [mailto:pgsql-performance-ow...@postgresql.org] On Behalf Of Andreas Joseph Krogh Sent: Monday, February 09, 2015 4:13 PM To: pgsql-performance@postgresql.org Subject: [PERFORM] Poor performance when deleting from entity-attribute-value type master-table Hi all. Using PG-9.4.0 I'm seeing this trying to delete from an entity-master table: *# explain analyze delete from onp_crm_entity where entity_id IN (select tmp.delivery_id from temp_delete_delivery_id tmp); QUERY PLAN --- Delete on onp_crm_entity (cost=0.43..5673.40 rows=1770 width=12) (actual time=7.370..7.370 rows=0 loops=1) - Nested Loop (cost=0.43..5673.40 rows=1770 width=12) (actual time=0.050..1.374 rows=108 loops=1) - Seq Scan on temp_delete_delivery_id tmp (cost=0.00..27.70 rows=1770 width=14) (actual time=0.014..0.080 rows=108 loops=1) - Index Scan using onp_crm_entity_pkey on onp_crm_entity (cost=0.43..3.18 rows=1 width=14) (actual time=0.010..0.011 rows=1 loops=108) Index Cond: (entity_id = tmp.delivery_id) Planning time: 0.314 ms Trigger for constraint onp_crm_activity_entity_id_fkey: time=4.141 calls=108 Trigger for constraint ... Trigger for constraint ... Trigger for constraint ... I have lots of tables referencing onp_crm_entity(entity_id) so I expect the poor performance of deleting from it is caused by all the triggers firing to check FKI-constraints. Andreas, do you have indexes on FK columns in child tables? If not – there is your problem. Regards, Igor Neyman
