Vlad, > PS Snapshot (concurrency) transaction guarantees that once read record > could be read again and will be the same. So, in theory, we can just > re-read same data page when looking for next record.
Why "in theory"? I don't see how the DP could change for the purposes of the next record for Snapshot transactions. Yes, the additional versions of the next record could be posted to the DP in the cache page (marking changes or deletions) but the "existence" of the record on the DP can't change within the snapshot. Only if the new record changes have "overflowed" to other DPs would other pages need to be loaded. It would seem that a significant performance improvement could be yielded by changing the current functionality. Sean ------------------------------------------------------------------------------ RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
