Exadata Storage Indexes

Storage Indexes is one of the most significant features of Exadata that run at the storage cells. However, is also the feature which is the least (if at all) controllable by the user (developer/dba). You cannot control when they will be build, for which columns they will be build for, and  for which columns the storage indexes will remain as the database workload evolves. So it is a true "black box" and totally different to what we have been used from good old database indexes.

The following links from Richard Foote's Oracle Blog are very insightfull on how storage indexes really work:
First goes the introductory series of posts:

• Exadata Strorage Indexes - part I
• Exadata Strorage Indexes - part II
• Exadata Strorage Indexes - part III
• Exadata Strorage Indexes - part IV
• Exadata Strorage Indexes - part V

And then is the comparison series between SIs and database indexes (check out the last one on the "magic" 8-column limit):

• Storage Indexes vs Database Indexes - part I
• Storage Indexes vs Database Indexes - part II
• Storage Indexes vs Database Indexes - part III
• Storage Indexes vs Database Indexes - part IV

Enjoy,
Oracle Learner.