Thread: BLOB question + MS Access ODBC issue

BLOB question + MS Access ODBC issue

From
jan@evation.com (Jan Branbergen)
Date:
Hi,

i have ported a lot of my applications to PostgreSQL in the last
months.

in the proces of porting the data, i have created a lot of BLOBs, and
in the next import run, i truncated the table which was referencing
the BLOB ( so i did not do a pg_lounlink for the object ).

this has happened numerous times, so i a worried about the following:
have the BLOBs become "zombie"-BLOBs ( that is: are they still
residing in my database ), or are they deleted with a VACUUM for
example? i could not find this is in the manual.

--

for something completely different: i have been tweaking the
odbc-driver for postgres to better support MS Access ( let's not
discuss why i need this, i need this ). for VB, DAO users: i
experienced that:

"
rs.AddNew
    rs.("Name") = "balbalklflkjsdlkfs"
rs.Update
rs.Bookmark = rs.Lastmodified
debug.print rs("id") // autonumber, serial
"

was not working: i could not retrieve the assigned serial/autonumber.
i have implemented a dirty fix for this. i do not consider this as a
major contribution which needs to propagated, just wanted to make
people aware of problem/solution.

regards,

Jan Branbergen
Evation.com

Re: BLOB question + MS Access ODBC issue

From
Tom Lane
Date:
jan@evation.com (Jan Branbergen) writes:
> in the proces of porting the data, i have created a lot of BLOBs, and
> in the next import run, i truncated the table which was referencing
> the BLOB ( so i did not do a pg_lounlink for the object ).

> this has happened numerous times, so i a worried about the following:
> have the BLOBs become "zombie"-BLOBs ( that is: are they still
> residing in my database ), or are they deleted with a VACUUM for
> example? i could not find this is in the manual.

They're zombies.  See the contrib/vacuumlo program for some help
cleaning them out.

            regards, tom lane