On Fri, 12 Mar 2010 04:07:21 +0100, Dumitru Daniliuc <d...@chromium.org>
wrote:
joao,
if i understand correctly, you basically want to have an automated system
implemented in the browser that decides when to vacuum databases (or at
least make sure it doesn't happen too often). and the vacuum() calls
would
be just one of the parameters that the system takes into account. i think
having such a system is fine, but doesn't need to be spec'ed. at the same
time, i think it's worth having a spec'ed vacuum() call that gives the
app
some guarantees. in particular, i would like the completionCallback to
be a
signal that the database is in a good shape and ready for more work. so
how
about this:
1. if the UA doesn't support the vacuum() call, go to step 3.
2. queue up a task to vacuum the database. if the UA decides that
vacuuming is not needed at this time, the vacuuming task scheduled in
this
step could be a no-op.
3. when the vacuuming task completes, queue up a task to invoke the
completion callback, if one was specified.
i think this spec should allow you to treat the vacuum() call as a hint,
while also guaranteeing that:
1. the UA believes the database is in a good shape when the completion
callback is called.
2. the completion callback is called as soon as UA believes the DB is in
a
good shape.
what do you think?
Looks better, and more flexible.
I wonder if sqlite has a way to query the number of pages in the freelist ?
Probably something like 10% of pages in the freelist would be a good
threshold to allow a vacuum.
thanks,
dumi
