Thanks Clemens -what do you mean by journal file is created only when needed ? Is it not true, that for any transactions it is always created. The documentation here https://www.sqlite.org/tempfiles.html says in exclusive mode it is created at the start of first transaction and not deleted until the exclusive mode is exited. So I am guessing in this mode ,a journal file should always be present ?
-I don't have journal mode setting. Again based on the documentation at https://www.sqlite.org/tempfiles.html the journal file should always be present. Please let me know if my understanding is wrong. My question is does a non zero size of journal file indicate its hot and has not been used to recover the transaction. I see the journal file at 15 mb in one case although the sqlite application is still running. What does that mean? After a transaction has been receovered using the journal file, should its size go to zero ? -is there a tool I could write to figure out if a journal file is hot or not and recover lost transactions from it ? -mayank -----Original Message----- From: sqlite-users-bounces at mailinglists.sqlite.org [mailto:sqlite-users-boun...@mailinglists.sqlite.org] On Behalf Of Clemens Ladisch Sent: Wednesday, July 15, 2015 5:43 AM To: sqlite-users at mailinglists.sqlite.org Subject: Re: [sqlite] journal file and its size Mayank Kumar (mayankum) wrote: > Sometimes we see the journal file not present on the system although > active transactions are ongoing. How is that possible since the > documentation says the journal file is always created in exclusive > mode ? The journal file is created only when it is needed. The journal file is not needed for the locking itself; the exclusive lock is on the database file. > sometimes on our customers setup, we have seen a journal file of size > 10-20MB. Does that mean that the journal is still hot and has not been > used to recover or rollback ? That depends on the PRAGMA journal_mode setting. In the default DELETE mode, the journal file would be deleted on the COMMIT, so it being there implies that it's hot. Regards, Clemens _______________________________________________ sqlite-users mailing list sqlite-users at mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
