Subject [firebird-support] Sweeping
Author Craig Stevens
Hi All,

Last week i asked about sweeping and the oit and oat. Curiously late friday i was monitoring this GAP value between OIT and OAT which had been steady and stable with a difference of 1 for most of the day. Then this GAP started to increase, going to >5000 then up to 18000..I looked at what our systems were doing at this time and everything was normal activity just like during the day while the GAP had stayed steady at 1. I continued to monitor and this GAP value continued to climg to 35000 then to 52000 and ultimately to over 68000. The firebird server cpu showed normal activity and usage during this difference and there was no impact on our system all be it Friday after 5pm. Eventually the GAP fell back down to around 700 not longer after. Does that sound normal for a Firebird 1.5 database server running on Windows 2000 server machine? I assume that although the GAP value was extremely high, it doesnt mean there is a lot of unresolved transactions? it just means that there is a transaction way back down the line that has not been fully dealt with? Also is sweeping a transaction and does that contribute to this GAP value while the sweep does its job, then once finished it goes away reducing the GAP value? Is there anyway to know when a Sweep is running, can you set up some notification when it occurs?

thanks
Craig