On Tue, Dec 20, 2011 at 6:08 AM, Simon Slavin <slav...@bigfraud.org> wrote: > > First, there's more than one way of using SQLite3 from PHP. There's also the > interface SQLite3:: which is a much thinner wrapper around the basic SQLite C > library. I have no way of knowing what proportion of programmers use one > library or the other.
I started using SQLite with PHP in version 5.2.x, when there wasn't SQLite3:: interface, so I chose to use PDO. Moreover, I don't want to lock myself into SQLite, PDO provides a somewhat more flexible approach. > As long as you set an acceptable timeout, which you do with one of these > calls depending which library you're using > > <http://php.net/manual/en/pdo.setattribute.php> > > <http://uk.php.net/manual/en/sqlite3.busytimeout.php> > > your web service probably isn't going to run into problems. What might be > worrying you right now is the result of the default timeout being zero, > something which is arguably weird. In other words, unless you specify a > timeout yourself any report of a lock is instantly treated like an error. > Set your timeout to one second or five seconds and the behaviour will be more > reasonable. I'd done some research into this since I asked my question and learned some things. According to http://bugs.php.net/bug.php?id=38182 and http://www.serverphorums.com/read.php?7,118071, PDO_SQLITE defaults to a 60 second busy timeout. This should be enough. > Second, most transactions and locks in SQLite from PHP are fleeting. > Generally you want your web page to list some records or do one update. You > wouldn't have a process keep a lock active for a long time because this would > correspond to your server taking a long time to show a web page, and nobody > wants that. So a lock by one process probably isn't going to last very long > -- probably a fraction of a second. Access for a web page is unlikely to > involve deadlock because of the nature of web pages: they generally don't > interact with the user while a transaction is open. One would think so :) But Drupal people have run into the opposite (http://drupal.org/node/1120020 and http://stackoverflow.com/questions/6108602/avoiding-locked-sqlite-database-timeouts-with-php-pdo). This seems to happen for them mostly when they are indexing their data a visitor to a site requests a page. Apparently, their indexing tasks is long running and write intensive. I think they should rework this tasks. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
