Thanks, This actually solves another problem also where the uid generation algorithm fails to generate a true uuid. Since table u has uuid column unique, my database will never have a uuid repeated. But the number of uuids I can have will now be dependent on what integer can accommodate (I am sure it's a large number and I hope my database will not consume all of it). Moreover, when the database no longer uses a uuid, it can be removed from this table too, which might mean a considerable work for application developer :-).
Regards, Prakash Reddy Bande Altair Engg. Inc, Troy, MI -----Original Message----- From: Scott Hess [mailto:[EMAIL PROTECTED] Sent: Wednesday, August 29, 2007 1:47 PM To: sqlite-users@sqlite.org Subject: Re: [sqlite] GUID/UUID in sqlite. In either case, if you use the UUID as a primary key in more than one table, you should consider having one table to convert the UUID to a 64-bit id, and use that as the primary keys on the other tables. If you have UUID as a primary key, your table will have 2 b-trees, one for the index of UUID to rowid, the other to map the rowid to row data. Once you have 2 such tables, it can be more efficient to break out the mapping of the UUID to an internal id you use elsewhere. Example, instead of: CREATE TABLE t ( uuid TEXT PRIMARY KEY, ... ); INSERT INTO t (uuid, ...) VALUES (?, ...); Do: CREATE TABLE u ( uuid TEXT UNIQUE, internalid INTEGER PRIMARY KEY ); CREATE TABLE t ( fk_internalid INTEGER PRIMARY KEY, ... ); BEGIN; INSERT INTO u (uuid, internalid) VALUES (?, NULL); INSERT INTO t (fk_internalid, ...) VALUES (LAST_INSERT_ROWID(), ...); COMMIT; -scott On 8/29/07, John Stanton <[EMAIL PROTECTED]> wrote: > You could experiment with making your 128 bit entity a BLOB. The > alternative would be to represent it it in ASCII. Changing its radix > would probably be the significant overhead, not the Sqlite storage. > > Prakash Reddy Bande wrote: > > Hi, > > > > I am designing a database where-in my column data is UUID. > > I am trying to figure out which is the best way to handle UUID since if > > stored as text the length would be 32 characters (though UUIDs are 128 > > bit size) and select query based on UUIDs might not be really fast (I > > might be wrong here.) > > > > Regards, > > > > Prakash Reddy Bande > > Altair Engg. Inc, > > Troy, MI > > > > ------------------------------------------------------------------------ ----- > > To unsubscribe, send email to [EMAIL PROTECTED] > > ------------------------------------------------------------------------ ----- > > > > > ------------------------------------------------------------------------ ----- > To unsubscribe, send email to [EMAIL PROTECTED] > ------------------------------------------------------------------------ ----- > > ------------------------------------------------------------------------ ----- To unsubscribe, send email to [EMAIL PROTECTED] ------------------------------------------------------------------------ ----- ----------------------------------------------------------------------------- To unsubscribe, send email to [EMAIL PROTECTED] -----------------------------------------------------------------------------
