= Index performance tests =

In this directory there are some performance tests for bitmap indexes,
compared to btree and hash indexes.

Performance tests are made for two types of operation (index build,
simple query), for various data patterns and for various index types.

== Data patterns ==

Since the distribution of data affects the behaviour of bitmap
indexes, we test the following patterns:

 * s = sparse 
   1M rows, 1k distinct values, adjacent values are distinct

 * o = ordered
   1M rows, 1k distinct values, each value repeated 10 times

 * f = few
   1M rows, 50 distinct values, adjacent values are distinct
