Theres alot of hype on OLAP, but I am unconvinced that there is one best way to keep or store the various disparate data in one common format or to centralise it? Is it always better to keep your data in OLAP for optimal read and writing for proc and data steps? Or do I have to resort to converting all the various sources to flat files, copy them to a local directory and run them locally off one common box to have optimal IO?
* moving a disk drive's read/write head (seeking)
* moving to a specific spot in a file on tape
* moving data.
Processing data means moving it from storage, to memory, into a processor's cache, into a processor's register, through transformation or detection circuitry (decision making), and ultimately back (especially if it's SAS) to storage. The less of this is done, the faster things happen.
System design is a practice in balancing system resource usage, time, money and politics (interactions of people, groups, and departments).
How this is done depends on your corporate/company's culture.
Some stuff is best kept in an RDMS -- Oracle, DB2, Sybase, SQL Server, MySQL, Access, FoxBase, InterBase, Paradox, Informix, etc.
Some stuff is best kept in a SAS permanent dataset.
Some stuff has to come from a VSAM file on a mainframe.
Some stuff has to come from SMF or RMF flatfile records on an mainframe.
Most stuff can be transferred from one thing to another.
Some things are best kept in a central repository -- Data Warehouse
Some things are best kept locally.
A good answer to this is within the realm of "Business Intelligence" and the idea of "Information Maturity". A topic also within SAS's world.
Best practice is generally to have a central repository -- Data Warehouse -- with a well managed MetaData layer/server to help normalize/control the data access. But, this is a seriously non-trivial exercise/experience. The results can be huge for the business, if done well. If not done well, etc. then it is a huge waste of money and time.
thanks. I suppose the reason to set the data in flat files is portability (you can even copy it to tape from one site and carry it to another). I wish all of this made more sense, but theres probably no one glove that fits all hands.
I found this youtube video about EG > SAS > DBMS interesting and very enlightening for a layman.