Poor performance in Database Reader Node

Hi all,

I use Database Reader Node for read almost 10 milion of row from Oracle Database 11g.

The driver I'm using is (ojdbc6.jar) "<entry key="driver" type="xstring" value="oracle.jdbc.driver.OracleDriver"/>

The query is very symple select c1, c2, c3... from my table.

The problem is that when I execute tho node it read almost 1,3 milion of row evey 30 minutes.

If I use sqldeveloper with the same  query downloads almost 1,3 milion of row in 10 minutes on the same pc.

Can someone help me?


thank 1m 









Hi Giorgio,

this might be due to different fetch sizes. The fetch size defines how many rows are read from the server per request. So increasing the fetch size reduces the server round trips making the fetching of rows faster but consumes more memory. I think the default fetch size for Oracle is 10.

To change the fetch size just add the following parameter to your knime.ini file with an appropriate fetch size:


This might do the trick.



Hi Tobias,

I'm trying to change fetch size today and then I'm sharing the result.


thank you very much



With higher fetch size the performances are a bit better.

I think the bproblem in in DB configuration or jdbc driver. I'm asking My dba.


thank you form time



Hi All,

I am using oracle 11g and have added the driver (ojdbc6.jar) manually through preference/Databasese/add file,but when i use the Database connector.

i am not able to view the driver which i have added. Any reason why i am not able to see in 3.3.1.

Any help on this will be really great.