As I explain in previews email, I think that recreating the index is the slowest operation I can do on my DB. Anyway in my first email I ask another question about -wal file Tryin to DELETE the (5 millions) records with the shell SQLITE interface I can see the -wal grow up till 600MB. I can not understand why the -wal is no more reintegrated, and even when I close the connection (closing the shell) -wal file still exist. Trying for example the statement "create table new as select * from current where condition = keep;" the -wal file grow up till 1,5GB and than the same, after closing shell the -wal remain.
Moreover the operation above "create new...." terminate with a "Error: disk I/O error" The hard disk I use has a lot of free space and it's SATA2 hard disk, so is internal Il 07/10/2010 20.38, Petite Abeille ha scritto: > On Oct 7, 2010, at 6:05 PM, Michele Pradella wrote: > >> I have a DB of about 3GB: the DB has about 23 millions of records. [..] >> the statement is trying to delete about 5 millions records and it takes >> about 4-5minutes. >> Is there a way to try to speed up the DELETE? > Considering that you want to delete about a quarter of the records, perhaps > it would be more efficient to recreate that table altogether, no? > > Pseudocode: > > create table new as select * from current where condition = keep; > create index on new; > drop table current; > alter table rename new to current; > > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > -- Selea s.r.l. Michele Pradella R&D SELEA s.r.l. Via Aldo Moro 69 Italy - 46019 Cicognara (MN) Tel +39 0375 889091 Fax +39 0375 889080 *michele.prade...@selea.com* <mailto:michele.prade...@selea.com> *http://www.selea.com* _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
