Hello.
Several months ago I ported the "free pages" code from sqlite v2 to
v3. I found the original at [1]. My copy is at [2]. I unsuccessfully
tried to contact the original author.
This code simply computes the amount of "slack space" in the
database. Our database will sometimes grow quite large and then most of
the rows will be deleted. We want to reclaim the space, but due to the
way our application works, it is not efficient to vacuum the database
right after we delete the rows in question. So, we periodically call
the "free space" routine and vacuum our database if the amount of slack
space exceeds a certain threshold. Good, bad or ugly, that is what we do :)
I would like to see this code ultimately merged into the official
sqlite database distribution (so that we are not distributing a "hacked"
version). However, I am not an sqlite genius. I would very much
appreciate some peer-review. (For example, I removed all of the
database integrity checks b/c the v2 code failed on a v3 system. I also
had to copy many struct definitions from other files as these structures
were not exposed via header files. These hacks seem ugly to me but I'm
not sure what to do about it).
I grant my code to the community. I can be licensed under the
current sqlite license. Your comments are appreciated. Thank you.
[1] http://web.utk.edu/~jplyon/sqlite/code/freepages.c
[2] http://unwg.no-ip.com/freepages.c
