Subject Database Size Is Not Reducing
Author Vishal Tiwari
Dear All,

I am using Firebird 2.5 database.

I have a table that has column of type Blob field, this table also contains some other columns.

The issue is, I had total 78,000 records in this table. What I did is as every record was containing image in it, I then ran an update query and set Null value to all the records for this blob column.

I then backed up the database using GBack and then restored. After restored the database there is no change in database size.

Any idea why it is so ?

I was referring to below link,



which says:
It is important to know and remember that in contrast to other fields, BLOBs data are not stored in the table record. Table records store only BLOB_ID, whereas BLOB body is kept in separate database tables.

Is because of this reason there is no change in database size?

If it so then, I am curious to know where does Firebird store the images?


Thanks In Advance.

With Best Regards.

Vishal