1)
If you are using a TOracleDataset you can set property QueryAllRecords := False;
2)
Or you can exclude you blob-field from the fields in the select statement (or double click the query and add all fields except for the blob field). You will then need another query to request only the blob field. This query can have the other table as a master table using the primary key as master/detail field(s).
This way you only fetch the blob field for the row that you need, and not for all rows.
I would suggest option 1) if you are not using a TDBGrid (or similar) to display your data. Otherwise I'd go for option 2)
