Query with blob fields very slow

chkaufmann · Post by **chkaufmann** » Sat 01 Jul 2006 11:49

Hi,

I have a query with about 12'000 records. One column is a blob field, in my case with about 100-1500 bytes of data.
Reading of this query/column is very slow. The tools I use:

Oracle 9
dbExpress Driver 2.1
Delphi 6

When I profile the critical routine, most of the time is lost here:

blob := myQuery.CreateBlobStream('GEOMETRY', bmRead); >> 27%
...
blob.Free; >> 70%

My question is, how can I speed it up:
- configuration on Oracle server ?
- configuration on Oracle database / table / column ?
- settings in driver ?
- other technologie, e.g. Oracle direct instead of dbExpress?

cu Christian

Plash · Post by **Plash** » Wed 05 Jul 2006 10:59

Performance will be improved greatly if you use ODAC instead of dbExpress.

chkaufmann · Post by **chkaufmann** » Wed 05 Jul 2006 11:24

plash wrote:Performance will be improved greatly if you use ODAC instead of dbExpress.

And there is no parameter, that has an influence on performance when using the CoreLab dbExpress driver?

cu Christian

Plash · Post by **Plash** » Fri 07 Jul 2006 09:09

Core Lab dbExpress driver has no parameters that influence on performance when reading BLOB data.