|Subject||Re: [Firebird-Architect] blobs causes table fragmentation.|
|Author||Ann W. Harrison|
>At 06:26 AM 10/5/2004, Pavel Cisar wrote:
>On 5 Oct 2004 at 10:27, Dmitry Yemanov wrote:
> > We have the very similar problem with "reserve" option in DPM. The engine
> > reserves up to 50% of the data page space for the subsequent updates.
>No, reserve is 20%.Sorry Pavel, the reserved space is one fragmented record header (16 bytes)
per primary* record stored on the page. With very large records, that's a
small percentage. With one character records, it's over 50%. And yes, it
might make sense to make the fill factor a table parameter rather than
a database parameter.
* primary records - the record version pointed to by the record id and index.
Fragments, back versions, and blobs don't count.