KeyMgtGetNextValueConcurrent and SDKSequences

[ORACLE_1]

Hello All,

I have a question regarding KeyMgtGetNextValueConcurrent routine and SDKSequences hash file.

We have multiple DataStage projects which in some cases are loading the same dimensions. In order to properly maintain surrogate keys between projects, what I did is, I created SDKSequences hash file at a different path other than project directory and created VOC entries for this hash file for both the projects.

It is working as expected. But I am curious on what happens when two projects are trying to generate surrogate keys using KeyMgtGetNextValueConcurrent routine at the same time. My initial thought is, I will be getting a failure. To test, what I did is, with the help of my colleague I tried generating surrogate keys for the same dimension by using Test functionality of the routine and surprisingly I did not get an error. Then is my assumption that "SDKSequences hash file cannot be accessed concurrently between different DataStage projects" incorrect?

Please let me know.

Thanks in advance!!

~Prakash.

[ray.wurlod]

Your assumption is indeed incorrect. Take a look at the code for the routine, to see how locking is handled. A row level lock is taken and held only for the duration of the update.