using hint in OCI stage

ayan · Post by **ayan** » Thu Apr 22, 2010 5:14 am

Hi,

Can we use hints in SQL query in OCI stage? If I specify a parallel hint for a select query (which does a full table scan),will datastage read faster?

Regards,
Ayan

Sainath.Srinivasan · Post by **Sainath.Srinivasan** » Thu Apr 22, 2010 5:26 am

Queries are passed to your RDBMS as they are mentioned. So the speed of the query is not relevant to DataStage by your Database.

From DataStage, you can configure your array fetch size to use returned data and memory efficiently.

ray.wurlod · Post by **ray.wurlod** » Thu Apr 22, 2010 6:44 am

To put that another way, DataStage itself does not use hints. So whether hints will make anything faster depends solely on whatever impact the hints will have in the database.

chulett · Post by **chulett** » Thu Apr 22, 2010 6:50 am

So yes, and it's all about Oracle not DataStage. Also note there's no need for custom SQL simply for this, I put the hint as part of the derivation of the first field and then the SQL will be generated all proper like, hint and all.