Modern indexes for modern data The age of data is here, and though it actually started several decades ago, we can say that data is evolving, perhaps too quickly, and the need to understand it is increasing. There is a lot of research on new trends, new ways to store a table, new ways to...
Sparse indexing has been around for a number of versions. The history of these on the z/Os side goes back to originally helping with non-correlated subqueries in V4, then star joins in V7, to hashing support of these indexes in V10. Since V10, I have seen more and more use of sparse...
Photo by Jenny Rollo Written by John Maenpaa, Senior Manager, Health Care Service Corporation. johnmaenpaa@db2solutions.org With the recent switch over to daylight savings time, I’ve been giving some thought to the idea that we should consider our timestamps more carefully. ...
DB2 V10 introduced the ability to include non-key columns in a unique index, allowing index only access without affecting the unique key. That's great for the transaction benefiting from index only access, but what about the other transactions that access this index? Can they be negatively...
EU13F12.pdf
Often a single-column index may not be of great help if there exists a composite index with 2 or more columns having the first column identical to one present in a single-column index. As these are of little use, the enclosed script provides an automated way to report in large environments on...
db2-script-to-aid-in-identifying-redundant-indexes.txt
Tired of presentations and looking at slide after slide after slide...? Want to see the real thing and how the new XML features in DB2 9 actually run? In this session I will project a DB2 command window (in a large font) and go through creating, populating, indexing, querying, and trouble...
EU07C03.flv