Hi Thomas, I am running classic firebird 2.1, but I don't think its GC as I ran both a sweep and a backup and still got the same, longer, time
On 29 July 2013 16:44, Thomas Steinmaurer <[email protected]> wrote: > ** > > > > I'm trying to understand why there is such a large difference in runtime > > between these 2 situations. > > firebird 2.1.5 > > > > run a script to create 130000 records in a table, then use it for a > while. > > Which means > > updates to some fields within that table. > > > > run "select * from table", takes around 4.8 seconds > > > > do a backup & restore of the database > > > > run "select * from table", takes around 0.3 seconds > > > > t > > he plan shows a natural scan in both cases, no other database usage > > If you are using an Firebird architecture with cooperative garbage > collection, e.g. Classic in Firebird 2.1 or Classic/SuperClassic in > Firebird 2.5, then the difference in execution time might be garbage > collecting out-dated record versions. > > MON$RECORD_STATS might give you a clue if a statement is actively > involved in garbage collection with Classic/SuperClassic. Due to the > nature of the MON$ tables being an activity snapshot for a certain > point-in-time, you may miss the statement. > > The Trace API will give you this information for continuous statement > execution, but as you might know, the Trace API has been added in > Firebird 2.5, which aren't using. > > -- > With regards, > Thomas Steinmaurer > http://www.upscene.com/ > > Professional Tools and Services for Firebird > FB TraceManager, IB LogManager, Database Health Check, Tuning etc. > > > -- Nick Upson, Telensa Ltd [Non-text portions of this message have been removed] ------------------------------------ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Visit http://www.firebirdsql.org and click the Resources item on the main (top) menu. Try Knowledgebase and FAQ links ! Also search the knowledgebases at http://www.ibphoenix.com ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/firebird-support/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/firebird-support/join (Yahoo! ID required) <*> To change settings via email: [email protected] [email protected] <*> To unsubscribe from this group, send an email to: [email protected] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
