Sybase IQ Indexes

Before you index your Sybase IQ data, you must understand Sybase IQindex types, how you create an index, how you decide what index types are best suited for the way you use the data in your database, and performance and resource issues related to indexing.

• Overview of Indexes
  Indexes improve data retrieval performance. Sybase IQ indexes differ from traditional indexes and are designed to accelerate queries in the data warehousing environment.
• Tools for Creating Sybase IQ Indexes
  You can create a column index explicitly using either of two tools.
• Criteria for Choosing Indexes
  The set of indexes that you define for any given column can have dramatic impact on the speed of query processing.
• Sybase IQ Index Types
  This section explores in depth the reasons you might use each of the column index types.
• Adding Column Indexes After Inserting Data
  When you create an additional column index, the CREATE INDEX command creates the new index as part of the individual table and as part of any join indexes that include the column. CMP and multicolumn HG indexes are the only exception to this rule.
• Using Join Indexes
  If you know that certain tables in the same database will typically be joined in a consistent way, you may want to create a join index for those tables.
• Size and Benefits of Join Indexes
  Before creating a join index, estimate its size and potential benefit.