Re: [SQL] rule's behavior with join interesting
On Wednesday 21 April 2004 21:07, Kemin Zhou wrote: Here I have a very simple case table1 table1_removed anotherTable create or replace RULE rec_remove as ON DELETE TO table1 do insert into table1_remove select old.*, a.acc from old g join anotherTable a on g.acc=a.other_acc; === the parser complained ERROR: relation *OLD* does not exist So I used select old.*, a.acc from table1 g join anotherTable a on g.acc=a.other_acc; This worked find. When I run delete on table1, 213 rows. tmp table received 213X213 = 45369 rows. each row is duplicated 213 times. The issue here is that although you can refer to values such as OLD.acc, OLD is not a table but more like single row. So, you probably want ...DO INSERT INSTO table1_remove SELECT old.*, a.acc FROM anotherTable a WHERE a.other_acc = OLD.acc; Your second example just ignored the OLD.acc altogether in the join, so of course you got an unconstraind join of 213 x 213. -- Richard Huxton Archonet Ltd ---(end of broadcast)--- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
Re: [SQL] rule's behavior with join interesting
Richard Huxton wrote: On Wednesday 21 April 2004 21:07, Kemin Zhou wrote: Here I have a very simple case table1 table1_removed anotherTable create or replace RULE rec_remove as ON DELETE TO table1 do insert into table1_remove select old.*, a.acc from old g join anotherTable a on g.acc=a.other_acc; === the parser complained ERROR: relation *OLD* does not exist So I used select old.*, a.acc from table1 g join anotherTable a on g.acc=a.other_acc; This worked find. When I run delete on table1, 213 rows. tmp table received 213X213 = 45369 rows. each row is duplicated 213 times. The issue here is that although you can refer to values such as OLD.acc, OLD is not a table but more like single row. So, you probably want ...DO INSERT INSTO table1_remove SELECT old.*, a.acc FROM anotherTable a WHERE a.other_acc = OLD.acc; Old is not a single row at all, it is a placeholder for the result set that is deleted in this case. The rule you probably want is: create rule rec_remove as on delete to table1 do insert into table1_remove select old.*, a.acc from anotherTable a where old.acc = a.other_acc; This unfortunately does NOT support all the other join types, since the parser does not let you use JOIN before any FROM and you have old already in your rangetable, even if you don't see it. Jan Your second example just ignored the OLD.acc altogether in the join, so of course you got an unconstraind join of 213 x 213. -- #==# # It's easier to get forgiveness for being wrong than for being right. # # Let's break this rule - forgive me. # #== [EMAIL PROTECTED] # ---(end of broadcast)--- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
[SQL] rule's behavior with join interesting
Here I have a very simple case table1 table1_removed anotherTable create or replace RULE rec_remove as ON DELETE TO table1 do insert into table1_remove select old.*, a.acc from old g join anotherTable a on g.acc=a.other_acc; === the parser complained ERROR: relation *OLD* does not exist So I used select old.*, a.acc from table1 g join anotherTable a on g.acc=a.other_acc; This worked find. When I run delete on table1, 213 rows. tmp table received 213X213 = 45369 rows. each row is duplicated 213 times. My question: Is it possible to bring in another table in a rule? Where am I wrong in this case. Certainly I don't want that duplications. My table1_removed contain a primary key for the id. The speed of doing the delete is also very slow apparently it has to do N-square inserts. I have very limited information to read on the manual of postgres. Any solution? Kemin ** Proprietary or confidential information belonging to Ferring Holding SA or to one of its affiliated companies may be contained in the message. If you are not the addressee indicated in this message (or responsible for the delivery of the message to such person), please do not copy or deliver this message to anyone. In such case, please destroy this message and notify the sender by reply e-mail. Please advise the sender immediately if you or your employer do not consent to e-mail for messages of this kind. Opinions, conclusions and other information in this message represent the opinion of the sender and do not necessarily represent or reflect the views and opinions of Ferring. ** ---(end of broadcast)--- TIP 8: explain analyze is your friend
