Thread: DELETE FROM A BLACK LIST
Hi all, I have a Blacklist table containing about 1000 ID to delete from another table (T1 about 1440294 records) If i use the SQL DELETE FROM T1 WHERE T1.ID IN (SELECT BLACKLIST.ID FROM BLACKLIST) the operation is very slow . There is a faster way to do the same operation?? Thanks Luca
On Wed, 5 Mar 2003 luca.scaramella@recom.it wrote: > > Hi all, > I have a Blacklist table containing about 1000 ID to delete from another > table (T1 about 1440294 records) > If i use the SQL > > DELETE FROM T1 WHERE T1.ID IN (SELECT BLACKLIST.ID FROM BLACKLIST) > > the operation is very slow . > > There is a faster way to do the same operation?? use EXISTS > > Thanks > Luca > > > > > > > ---------------------------(end of broadcast)--------------------------- > TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org > -- ================================================================== Achilleus Mantzios S/W Engineer IT dept Dynacom Tankers Mngmt Nikis 4, Glyfada Athens 16610 Greece tel: +30-210-8981112 fax: +30-210-8981877 email: achill@matrix.gatewaynet.com mantzios@softlab.ece.ntua.gr
> > I have a Blacklist table containing about 1000 ID to delete from another > table (T1 about 1440294 records) > If i use the SQL > > DELETE FROM T1 WHERE T1.ID IN (SELECT BLACKLIST.ID FROM BLACKLIST) > > the operation is very slow . > > There is a faster way to do the same operation?? > Try DELETE FROM T1 WHERE T1.ID = BLACKLIST.ID It really works. Regards, Christoph
You could use where exists. delete from t1 where exists (select id from blacklist as b where b.id = t1.id) HTH Chad ----- Original Message ----- From: <luca.scaramella@recom.it> To: <pgsql-sql@postgresql.org> Sent: Wednesday, March 05, 2003 3:45 AM Subject: [SQL] DELETE FROM A BLACK LIST > > Hi all, > I have a Blacklist table containing about 1000 ID to delete from another > table (T1 about 1440294 records) > If i use the SQL > > DELETE FROM T1 WHERE T1.ID IN (SELECT BLACKLIST.ID FROM BLACKLIST) > > the operation is very slow . > > There is a faster way to do the same operation?? > > Thanks > Luca > > > > > > > ---------------------------(end of broadcast)--------------------------- > TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org >