Size and Benefits of Join Indexes

Before creating a join index, estimate its size and potential benefit.

• How to Estimate Join Index Size
  Sybase IQ provides a stored procedure, sp_iqestjoin, to help you estimate the size of a join index.
• How to Determine Join Index Benefits
  When considering creating a join index, compare the number of rows in the top table to the number of rows in the related table(s).