|Subject||Re: [firebird-support] Dump blobs from GDB File - Part II|
>> How can I read a blob stored in a data page ?The way I've been doing ? That means that Level 1 blobs and Level 2 blobs are stored in "BLOBS PAGES" ?
> Here's part of the answer.
> Blobs can be stored in up to three levels.
> Level 0 blobs contain the blob data. In that case, the bytes
> following the blob header are actual data, complete with the length
> words we talked about earlier.
> Level 1 blobs are arrays of page numbers of level 0 blob pages.
> Level 2 blobs are arrays of page numbers of level 1 blobs.
> So, if your header says level 0, just read the data. If it says
> level 1, then you've got a multi-page blob, and you'll find it the way
> you've been doing.
Now I can read blobs level 0 from data pages. Great :) But I've tested my dump tool on a functionnal database and with a SELECT COUNT(*) FROM TABLE I get 123326 records (with a blob per record). With my tool I'm able to retrieve 121572 interesting blobs either in blobs pages or in data pages (level 0). Does that mean that there are 2000 blobs with level 1 or 2 stored elsewhere ?
Really thanks Ann, have a nice week end :)