:-D
one more question : if i create primary key on my table and then import the data (assuming i used transactions) will my import be faster or slower vs the case where i import the data first and then create key (foreign key ??) and index the table. the point is that i need my import to be faster. i have 3890660 rows to import and row van be up to 50M large, so it's taking a pretty long time thnx Kees Nuyt wrote: > > On Thu, 19 Mar 2009 02:54:34 -0700 (PDT), baxy77bax > <b...@hi.htnet.hr> wrote: > >> >>hi my question is : if i create table that contains primary key like; >> >>create table TEST (field1 varchar not null primary key); >> >>do i need to create index on it or not? > > No, the primary key implies an index will be created > automatically. > >>and is it better to create table with a primary key and then import data in >>it or create table without a key , import data and then just create index on >>the table. (which is faster- or should i ask which is the fastest way to >>import data in the table?) > > You can't add a primary key afterwards. > > The best way is to create the table with the primary key and > then insert records sorted by the primary key field. > For speed you also have to wrap the INSERT statements in a > transaction (BEGIN; INSERT; ......... INSERT; COMMIT;). > > If you want to use the .import command of the SQLite command > line tool, you would sort the import file beforehand on the > primary key column. > >>then if i create proper table , is it advisable to order data by >>column with primary key on it or data with index on it. > > In your case (with a primary key on a text column) that > won't make a difference, I think. > >>thank you > -- > ( Kees Nuyt > ) > c[_] > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > :-D:-D -- View this message in context: http://www.nabble.com/is-primary-key-already-indexed---tp22596778p22600402.html Sent from the SQLite mailing list archive at Nabble.com. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
