Subject | Re: [firebird-support] Blob segment size and Filesystem block size |
---|---|
Author | Ann W. Harrison |
Post date | 2005-04-19T14:24:24Z |
Nigel Weeks wrote:
higher level programs as a suggested size for an allocated buffer. You
can, of course, choose the segment size you want to write. Typically
the engine writes everything up to 16K as a single segment.
Blobs are stored on database pages, making the segment size the same as
the file system block size will have no effect on the size of a write -
Firebird always writes page sized blocks. Making the segment size the
same as a page is also a bad idea, because the page has a certain amount
of overhead - about 20 bytes, if I remember, but subject to change.
Regards,
Ann
> I was just wondering if having the segment size of BLOBs the same as theFirebird totally ignores segment size. The attribute is available for
> filesystem block sizes yields any benefits?
> Or does Firebird completely disregard the segment size when storing
> to;retrieving from disk.
higher level programs as a suggested size for an allocated buffer. You
can, of course, choose the segment size you want to write. Typically
the engine writes everything up to 16K as a single segment.
Blobs are stored on database pages, making the segment size the same as
the file system block size will have no effect on the size of a write -
Firebird always writes page sized blocks. Making the segment size the
same as a page is also a bad idea, because the page has a certain amount
of overhead - about 20 bytes, if I remember, but subject to change.
Regards,
Ann