Deleting millions of rows every night
Hello all, We are going to be using MonetDB as a data mart between our data warehouse and our front-end applications and are planning to insert and delete several millions of rows from MonetDB every night as part of our data update cycle. We've noticed that MonetDB doesn't support the TRUNCATE statement so we're deleting all the data with DELETE FROM table. But is this the best way to delete millions of rows every night? Won't performance or free disk space degrade over time? Best regards, Dennis Pallett
On Mon, Jul 29, 2013 at 08:54:27AM +0200, Dennis Pallett wrote:
Hello all,
We are going to be using MonetDB as a data mart between our data warehouse and our front-end applications and are planning to insert and delete several millions of rows from MonetDB every night as part of our data update cycle. We've noticed that MonetDB doesn't support the TRUNCATE statement so we're deleting all the data with DELETE FROM table. But is this the best way to delete millions of rows every night? Won't performance or free disk space degrade over time?
A 'DELETE ALL FROM table' is very similar to truncate and indeed will cleanup all diskspace taken by the old rows. A Delete with a where clause however, will leave data on disk behind. Niels
Best regards, Dennis Pallett _______________________________________________ users-list mailing list users-list@monetdb.org http://mail.monetdb.org/mailman/listinfo/users-list
-- Niels Nes, Centrum Wiskunde & Informatica (CWI) Science Park 123, 1098 XG Amsterdam, The Netherlands room L3.14, phone ++31 20 592-4098 sip:4098@sip.cwi.nl url: http://www.cwi.nl/~niels e-mail: Niels.Nes@cwi.nl
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