On 10/27/11 11:11 AM, dsaunders1971 wrote:
I have a question about why Firebird writes / or changes so much data in the
database file when you run a simple select query.
Two things come immediately to mind:
1) Everything gets read and written to the file system in blocks. So
even if you just
On Thu, Oct 27, 2011 at 11:11 AM, dsaunders1971 dsaunders1...@yahoo.comwrote:
I have a question about why Firebird writes / or changes so much data in
the database file when you run a simple select query.
Firebird doesn't write anything to disk for a Select, unless cooperative
garbage
Two things come immediately to mind:
In addition to Doug 2 items, there is one other item:
Garbage Collection -- Due to the MVCC nature of the engine, SELECT queries can
find back-versions of records which need to be cleaned up. Depending on the
version (Superserver, Classic and
Doug Chamberlin chamberlin.d...@gmail.com wrote:
Two things come immediately to mind:
1) Everything gets read and written to the file system in blocks. So
even if you just update one byte in one record at least one whole block
is read and written. Of course, that is subject to caching, etc,