Wow! This is quite cool. Of course, it prompts another question or two: Instead of attaching the database to a file, is it possible to attach to a TCP socket?
If so, then if there are two instances of SQLite running in-memory databases (with identical schema) in two separate processes (same or different computers), is there already a similar method to copy the databases from one process to another (either by a pull model or a push model)? Or does one have to set up the plumbing and the handshaking first? If this is possible, then it may be possible to get some form of "high-availability" with a dozen lines of SQLite code. THAT appeals to my desire for simplicity (and perhaps to my laziness). Curiously, Jay Godse ----- Original Message ----- From: "D. Richard Hipp" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Friday, March 12, 2004 7:37 PM Subject: Re: [sqlite] Question about in memory db's > Keith Herold wrote: > > Is there a fast way to dump the in-memory db to disk, *and* periodically > > reload the file into an in-memory db? > > > > The ATTACH command can be used for this. > > Suppose you do an sqlite_open() on the in-memory database > and you want to transfer the complete contents of an > in-memory table XYZ to an on-disk database named "abc.db" > You can do something like this: > > ATTACH 'abc.db' AS external; > BEGIN; > DELETE FROM external.xyz; > INSERT INTO external.xyz SELECT * FROM xyz; > COMMIT; > DETACH external; > > The same technique works in reverse to load an in-memory > table from disk: > > ATTACH 'abc.db' AS external; > BEGIN; > DELETE FROM xyz; > INSERT INTO xyz SELECT * FROM external.xyz; > COMMIT; > DETACH external; > > Use WHERE clauses creatively if you only want to transfer > part of the data. > > Note that it is not necessary to ATTACH and DETACH every > time you want to do this. If you are always using the > same external database file, you can just ATTACH it once > when you open the in-memory database and it will always > be there for you. > > -- > D. Richard Hipp -- [EMAIL PROTECTED] -- 704.948.4565 > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
