Performance degredation when applying functions to selected columns on remote ODBC tables (multi-tab
Hi,
I wonder if anyone can shed any light on this, please.
We have an Oracle 9i (9.2.0.8.0) database talking to a DB2 (v7r1) database on iSeries via 10g Gateway Heterogeneous Services (dblink) using the DataDirect driver and are experiencing significant performance degradation when seemingly any manipulation (functions/concatenation) of the selected column(s) is applied. We have some means to circumvent this (e.g. pl/sql manipulation) but I'm intrigued as much as anything as to what is going on.
Queries like:
SELECT column2
FROM detail_table dt,
master_table mt
WHERE mt.column1 = dt.column1
AND mt.column3 = '10'
I wonder if anyone can shed any light on this, please.
We have an Oracle 9i (9.2.0.8.0) database talking to a DB2 (v7r1) database on iSeries via 10g Gateway Heterogeneous Services (dblink) using the DataDirect driver and are experiencing significant performance degradation when seemingly any manipulation (functions/concatenation) of the selected column(s) is applied. We have some means to circumvent this (e.g. pl/sql manipulation) but I'm intrigued as much as anything as to what is going on.
Queries like:
SELECT column2
FROM detail_table dt,
master_table mt
WHERE mt.column1 = dt.column1
AND mt.column3 = '10'
0