The following bug has been logged online: Bug reference: 3479 Logged by: Tiago Jacobs Email address: [EMAIL PROTECTED] PostgreSQL version: 8.2.4 Operating system: Linux 2.6.21.5 Description: contraint exclusion and locks Details:
Hi People! Connection #1 create table tab (dt_tab date); create table tab_2 () inherits (tab); create table tab_1 () inherits (tab); alter table tab_2 add constraint constraint_x check (dt_tab >= '20070701'); alter table tab_2 add constraint constraint_y check (dt_tab <= '20070731'); alter table tab_1 add constraint constraint_x check (dt_tab >= '20070601'); alter table tab_1 add constraint constraint_y check (dt_tab <= '20070630'); explain select * from tab where dt_tab = '20070705'; >"Result (cost=0.00..73.50 rows=22 width=4)" >" -> Append (cost=0.00..73.50 rows=22 width=4)" >" -> Seq Scan on tab (cost=0.00..36.75 rows=11 width=4)" >" Filter: (dt_tab = '2007-07-05'::date)" >" -> Seq Scan on tab_2 tab (cost=0.00..36.75 rows=11 width=4)" >" Filter: (dt_tab = '2007-07-05'::date)" Connection #2 begin; lock table tab_1 in exclusive mode; TrUNCATE TABLE tab_1; Connection #1 explain select * from tab where dt_tab = '20070705' oh-ow... It waits while the table (That is not used) is locked. Even that the final plan dont use tab_2007_07, it wait for unlock of table for make the plan. So, if I`m running a VACUUM on specific table, all the querys on the "master" table don't work. Best Regards, Tiago ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
