Subject Re: [firebird-support] Firebird Embedded version generates big files
Author Helen Borrie
At 09:18 AM 20/03/2012, kokok_kokok wrote:
>I am using FB
>An application process works fine when FB as service.
>When I use the same application but FB is embedded mode, the same process is slower and enlarge the size if database 40% more.
>Also, then the backup is a lot slower.
>Is there something that I can try or test to get similar performance in both options (embedded and service) ?

I think it depends on what you are comparing. If you are comparing 2.5 embedded (Superclassic, with cooperative garbage collection and only one user to carry the whole G.C. load) with Superserver (background and/or cooperative G.C., with multiple users to share the cooperative G.C. load, if it is enabled) then it is apples vs oranges.

The performance slowdown, the bloating of the database and the slowness of the backup all suggest buildup of uncollected (or uncollectable) garbage. Try running a backup with the -g switch (no_garbage_collection) and compare with the time taken for a backup done without it.

If you're getting major buildup of garbage from a stand-alone user, one has to suspect that the problem involves use of Commit Retaining and/or one or more long-running read-write transactions. If so, you have double jeopardy.