On Wed, 26 Feb 2020 15:35:16 +0100 I wrote: > The idea of the failsafe comparison is valid but it depends on how they have > configured journalling. Under light load the cost of journalling will > have limited impact as it will almost certainly be cached.
The journalling documentation is here. http://docwiki.embarcadero.com/InterBase/2020/en/Enabling_Journaling_and_Creating_Journal_Files It seems to contain two contradictory statements. On the one hand it says: > The journal file I/O is always synchronous and cannot be altered and in an earlier section on the same page we can read about the PAGE CACHE setting: > Determines the number of journal pages that are cached to memory. This > number must be large enough to provide buffers for worker threads to write > to when the cache writer is writing other buffers. It defaults to a hundred buffers. My reading of that is that there is only one cache writer, and journal writes are queued in the memory cache until they are finally written out to disc. The only different to Firebird's asynchronous writes that I can see is that journalling uses its own cache instead of the filesystem cache. Paul -- Paul Reeves http://www.ibphoenix.com Supporting users of Firebird Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
