[SAP Sybase ASE Source] Why does "trunc log on chkpt" option need to be false ?

[iti-attunity-sup]

Hello.

My Customer is using SAP Sybase ASE as a source.
In following prerequisites, it is stated that "trunc log on chkpt" option need to be false.
https://help.qlik.com/en-US/replicate/November2023/Content/Replicate/Main/SAP%20Sybase%20ASE/prereq_...

Would by tell me the reason why "trunc log on chkpt" option need to be false?

Best Regards.

[iti-attunity-sup]

Hello John-san

Sorry, following is mistake.
>Though "secondary truncation point" is set, why "trunc log on chkpt" need to be set true.

Correct quetions is following,
Though "secondary truncation point" is set, why "trunc log on chkpt" need to be set false.

Best Regards.

[john_wang]

Hello @iti-attunity-sup ,

>> Though "secondary truncation point" is set, why "trunc log on chkpt" need to be set false.

trunc log on chkpt is Sybase database itself behavior, it's totally out of Qlik Replicate control and it's higher priority than Qlik Replicate operations. So in summary:

1- turn off Sybase itself auto-trunc log function

2- on behalf of Sybase, call the secondary truncation point option via Qlik Replicate

Regards,

John.

[iti-attunity-sup]

Hello John-san
Thank you for your reply.

In our environment, I tried following.
・While stop task, executed DML in state of setting "trunc log on chkpt" true.
・After that execute checkpoint.

In this state, I resumed task, but error didn't occur.

I recognize that as specification, "secondary truncation point" is given priority over setting "trunc log on chkpt" to true on Sybase database.

So, Is "trunc log on chkpt" need to be false?
If error occurs, I want to know the case.

Best Regards.

[john_wang]

Hello @iti-attunity-sup ,

Maybe a simple sanity test cannot trigger any error but a regression test or heavy pressure test with volume data will show us the significant difference.

Thanks,

John.

[iti-attunity-sup]

Hello John-san
Thank you for your reply.

My customer and I recognize following as Sybase specification
・By setting "secondary truncation point", Sybase database doesn't truncate unread transaction log.
・"secondary truncation point" is given priority over setting "trunc log on chkpt" to true.

Is this wrong ?
I would like you to answer Yes or No.

Best Regards.

[john_wang]

Hello @iti-attunity-sup ,

I'm guessing I did not get the question well this time... however the scenario of setting "trunc log on chkpt" to true is NOT supported.

Regards,

John.