topic Re: BTree/Bitmap index equivalent in SAS datasets in SAS Enterprise Guide

BTree/Bitmap index equivalent in SAS datasets

deleted_user — Fri, 24 Apr 2009 05:54:12 GMT

Quick question - Like how in ORACLE, we have different types of indexes like Bitmap and Btree, is there anything like this in SAS datasets.
What we are trying to acheive is , for low cardinality columns , have a bitmap index and for high cardinality ones use Btree.Any thoughts?

Re: BTree/Bitmap index equivalent in SAS datasets

sbb — Fri, 24 Apr 2009 11:57:27 GMT

Using the Google advanced search argument listed below, I found several topic-related technical papers relevant to the subject of your post at the SAS support http://support.sas.com/ website which may be useful:

cardinality bitmap btree site:sas.com

Scott Barry
SBBWorks, Inc.

Re: BTree/Bitmap index equivalent in SAS datasets

LinusH — Fri, 24 Apr 2009 14:17:26 GMT

For Base SAS tables, there is just ordinary B-Tree indexes available. So there is not much to do there I'm afraid.

But for SPDE and SPD Server table, a so called Hybrid index is used, which will pick the best from both worlds, B-tree and bitmap. The best part is that you don't have to chose, you will get the best performance without having to decide/know the cardinality of data on beforehand. See on-line doc for mode details.

/Linus Message was edited by: Linus H