Re: SQLite Clarification
On Monday 31 July 2006 16:05, Clif Flynt wrote:
> The database file is only locked for the duration
> of the write operation - not while the database is open. A write
> normally takes a few milliseconds, then the lock goes away.
The issue here is that you may need write to have priority since there is
potentially a backlog building in the kernel. If the backlog gets too big you
will get a panic. The write operation has to be fast.
But suppose there are readers. Does the write block or fail? More of a
curiosity to me.
> Why is 256 bytes of data for each 1MiB of database a problem?
> Is memory so short and databases so large that this might cause
> a problem?
Database could be huge. A paranoid admin could easily get gigabytes of data in
a short time. Or maybe someone that wrote a rule that captures too much data
could run into a problem.
> If it is, then increase the page size from the default 1K.
> The actually usage is 2 bits per page of data. So if pages
> are 32KiB bytes instead of 1KiB, a 1MiB database only needs
> 8 bytes of storage for the bitmap.
This is good to know. That would probably help.
-Steve