topic Inquiring about Fetch Buffer Size tuning for Oracle Source (Full Load performance) in Qlik Replicate

Inquiring about Fetch Buffer Size tuning for Oracle Source (Full Load performance)

iti-attunity-sup — Thu, 14 May 2026 09:21:52 GMT

[Question]
We are using Oracle as a source database. Is it possible to specify or change the "Fetch Buffer Size" through the Qlik Replicate GUI or configuration files?

[Background]
We are considering adjusting the fetch buffer size as part of performance tuning to reduce Full Load processing time. In a different environment, we conducted verification by modifying the ODBC driver settings. However, our current environment uses the Oracle Instant Client (Oracle Endpoint), which prevents us from configuring settings via ODBC.

Could you please advise if there are ways to control the fetch buffer size within Qlik Replicate, or if there are any recommended alternative methods to achieve similar tuning?

Best Regards
Hironori Fujihira

Re: Inquiring about Fetch Buffer Size tuning for Oracle Source (Full Load performance)

john_wang — Thu, 14 May 2026 13:52:49 GMT

Hi Team,

Could you please share the database type of the target endpoint?

thanks,

John.

Re: Inquiring about Fetch Buffer Size tuning for Oracle Source (Full Load performance)

iti-attunity-sup — Fri, 15 May 2026 02:32:50 GMT

Hi John.

The database for the Target Endpoint is also “Oracle”.

Best Regards
Hironori Fujihira

Re: Inquiring about Fetch Buffer Size tuning for Oracle Source (Full Load performance)

john_wang — Fri, 15 May 2026 03:22:09 GMT

Hi Hironori Fujihira, @iti-attunity-sup

For Oracle-to-Oracle replication, we would recommend using Parallel Load to improve Full Load performance rather than relying primarily on parameter tuning.

Hope this helps.

John.

Re: Inquiring about Fetch Buffer Size tuning for Oracle Source (Full Load performance)

DesmondWOO — Fri, 15 May 2026 09:06:18 GMT

Hi Fujihira san, @iti-attunity-sup ,

I am unable to find the internal parameter for Fetch Size. If you want to change this Oracle parameter, please check with your Oracle DBA to see if oraaccess.xml could help in this case. However, please note that this parameter change will affect other applications as well.

Regards,
Desmond