HI Dmitry, thanks, I thought that there should not be a second sweep run but needed to make sure
And, transactions does not "holding the transaction counter". maybe I said it badly, I meant that: If I start a transaction, until I commit or rollback that stops the OAT moving forward (holding the active transaction counter I intended to say) can you help with this? : gbak can cause a gap > 20000, can that cause a sweep to be started when another process 'notices' the gap? On 14 January 2013 14:55, Dmitry Kuzmenko <k...@ibase.ru> wrote: > ** > > > Hello, Nick! > > Monday, January 14, 2013, 6:39:33 PM, you wrote: > > NU> I'm think of something like this: > NU> process A starts a transaction & holds it open, holding the transaction > NU> counter > NU> (time & transactions pass) > NU> process B starts a transaction, sees gap > 20000 & initiates sweep > ... > No, completely. > > Process A starts a transaction, engine checks Next, OAT, OST, etc, > and if there is a sweep gap greater than sweep interval, starts sweep. > This happens at the start of transaction, and this operation > is not parallel. > > So, when next transaction will start, auto-sweep already will be active, > and will not start second time. > > And, transactions does not "holding the transaction counter". > > Have you heard about windows function InterLockedIncrement? > Transaction start is like this. > > NU> On 14 January 2013 14:30, Dmitry Kuzmenko k...@ibase.ru> wrote: > > >> ** > > >> > >> > >> Hello, Nick! > >> > >> Monday, January 14, 2013, 5:52:49 PM, you wrote: > >> > >> NU> if 2 processes both see a gap > 20000 will that result in 2 sweeps > >> running > >> NU> at the same time? > >> > >> transaction start is serialized, i.e. no 2 transactions can start at > >> the same time. So, auto-sweep can not run 2 times at once. > >> Only first transaction start, that will discover "sweep interval", > >> will initiate auto-sweep (if it is not turned off by sweep interval = > >> 0). > >> > >> -- > >> Dmitry Kuzmenko, www.ib-aid.com > >> > >> > >> > > -- > Dmitry Kuzmenko, www.ib-aid.com > > > -- 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: firebird-support-dig...@yahoogroups.com firebird-support-fullfeatu...@yahoogroups.com <*> To unsubscribe from this group, send an email to: firebird-support-unsubscr...@yahoogroups.com <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
