Subject RE: [firebird-support] Database Size + OH NO ! not Sweeping troubles again
Author Alan McDonald
> Hi All,
> Please correct me if i am wrong, but if i have a database that
> contains many records and one table is a list of blobs {data mainly
> jpegs} that are deleted from time to time from the table, the
> effective size of the database reported by the OS would decrease with
> the deletion of this blob data. I have a database which i add data,
> then later remove the jpegs from the blob table once i buyrn to cd.
> However the database does not seem to reduce in size.
> I have done some reading on Sweeping etc etc and this is what the
> database is reporting to me
> Sweep Interval = 20000
> Forced Writes are on
> Transaction - oldest = 24112
> Transaction - oldest active = 24113
> Transaction - oldest snapshot = 24112
> Transaction - Next = 419254
> I ran a manual sweep on the database that does not seem to have had
> any impact. My question is am i wrong about the database resizing ?
> and does the data above tell me something that i should be aware of ?
> Thanks
> Craig

yes - you are wrong.
Deletes will declare space for re-use but neither deletes, nor sweep will
physically reduce the file size. Only back/restore will reset the file size.