topic Re: Joining data from multiple data sources in SAS Data Management

Joining data from multiple data sources

LucV — Mon, 17 Oct 2016 15:16:47 GMT

Hello,

Is it possible to use SAS to join the data from multiple data sources (for instance Teradata, SQL Server, Hadoop)?

Preferrably by writing SQL Select queries.

The data volumes in all datasources are high (GBs) and we need to minimize data replication.

Thanks a lot,

Lucian

Re: Joining data from multiple data sources

LinusH — Mon, 17 Oct 2016 15:56:27 GMT

Yes. Syntactically it's standard functionality.
But how to optimise it is a total different question and need a detail analysis.

Re: Joining data from multiple data sources

LucV — Mon, 17 Oct 2016 17:11:33 GMT

Thank you Linus. Any readings you could recommend for optimizing such queries, please?

Regards,

Re: Joining data from multiple data sources

LinusH — Mon, 17 Oct 2016 18:13:16 GMT

Not knowing about your general understanding of SAS/ACCESS processing, but I recommend first to get familiar with the documentation for your databases. Pay special attention to the difference between implicit (libname) and explicit SQL pass-through.

There are chapters in the documentation that discuss how to put processing done to the underlying DBMS, like joins.

But it's a special case when you have large volumes of data to join between different locations. The data needs to at some point be in a common place to make the join executed. Where that location depends on your specific situation, data, requirements, constraints etc.

Apart from doc there have been several SAS Global Proceedings papers discussing ACCESS to RDBMS and Hadoop.