On Thu, Mar 28, 2013 at 8:24 AM, ibrahim <ibrahim.a...@googlemail.com> wrote: > On 28.03.2013 13:09, Jeff Archer wrote: >> >> On Wed, Mar 27, 2013 at 6:35 PM, Simon Slavin <slav...@bigfraud.org> >> wrote: >>> >>> Reasonable figures. With 5764 writes to the disk in separates >>> transactions you have quite a lot of reading of data plus 5764 attempts to >>> update the database file. The updates have to be done in the right order, >>> and each update has to wait for the disk to be rotated into the right >>> position, though each update changes only a small amount of data (probably >>> two sectors). >> >> But my most basic question remains. Why is single transaction faster >> than PRAGMA journal_mode = off? >> >> Seems to me that with no journal there should only be single set of >> writes to the actual db and that journaling would double the number of >> writes because data has to be written to journal file as well. >> >> 2.5 sec with journal >> 5.5 sec without journal <= seems like this sould be the smaller number >> > You should read the sections 3 forward. > > http://www.sqlite.org/atomiccommit.html > > A single transaction happens mostly in memory then is flushed to the OS > Cache in one step. The Journal file (the amount of pages that will be > changed) is small while inserting new data into a database and the OS File > Cache is usually large enough ... >
Yes, I have read this. (And now re-read it) So, since much more work must be done when using journal file, why does it take longer to do the inserts when there is NO journal file? _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
