Where did you see this? It's inaccurate, and if I can, I'll remove it. If you want to use a proper asynchronous statement execution which wraps your statement[s] in a transaction, you want to use this: https://developer.mozilla.org/En/Storage#Asynchronously
Cheers, Shawn Wilsher Mozilla Developer On Thu, Dec 31, 2009 at 8:53 AM, Bert Nelsen <bert.nel...@googlemail.com>wrote: > Hello, > > I would like to make writes to my SQLite db faster. > > I was thinking about the Async method, but I think I remember reading > somewhere that it may cause database corruption. > > Now I read something on the Mozilla pages, and I don't understand what > exactely they are doing. > > Do they bundle everything in transactions only or do they in fact use the > Async method? > It is not clear to me by reading through their articles. > > It would be nice if somebody could clear me up on this issue. > > Here is the article: > > Lazy writing > > Mozilla has relaxed the ACID requirements in order to speed up commits. In > particular, we have dropped durability. This means that when a commit > returns, you are not guaranteed that the commit has gone through. If the > power goes out right away, that commit may (or may not) be lost. However, > we > still support the other (ACI) requirements. This means that the database > will not get corrupted. If the power goes out immediately after a commit, > the transaction will be like it was rolled back: the database will still be > in a consistent state. > > Higher commit performance is achieved by writing to the database from a > separate thread (see > storage/src/mozStorageAsyncIO.cpp< > http://mxr.mozilla.org/mozilla-central/source/storage/src/mozStorageAsyncIO.cpp > > > which > is associated with the storage service in > storage/src/mozStorageService.cpp< > http://mxr.mozilla.org/mozilla-central/source/storage/src/mozStorageService.cpp > > > ). > The main database thread does everything exactly as it did before. However, > we have overridden the file operations and everything comes through the > AsnycIO module. This file is based on > test_async.c<http://www.sqlite.org/cvstrac/rlog?f=sqlite/src/test_async.c > >from > the sqlite distribution. > > The AsyncIO module packages writes up in messages and puts them on the > write > thread's message queue. This write thread waits for messages and processes > them as fast as it can. This means that writes, locking, and most > importantly, disk syncs, only block the AsyncIO thread. Reads are done > synchronously, taking into account unwritten data still in the buffer. > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
