Based on the Block Selectivity, this option analyzes all indexes in the
database, excluding Bitmap and Domain indexes, generates a non-selective
indexes report and scripts to drop all non-selective indexes based on the
report.
The index block selectivity is calculated using the following formula:
block selectivity for an index (BS) = (Average data blocks per index /
number of data blocks in the table) * 100
An index is considered non-selective if the following condition is
true:
BS > 15 or the number of objects in the table is less than 500.
If either of these conditions are met, an index is considered
non-selective, and it will show up when you select the View Report tab in
this page . You can drop all the non-selective indexes by selecting the
Drop Indexes tab in this page.
Note: To generate a report and drop index
script, you should analyze the entire database schema using the
Tools>Analyze and select the Compute
Statistics option.