SQL/MX 2.x Reference Manual (H06.04+)

Metadata Tables
HP NonStop SQL/MX Reference Manual—540440-003
10-78
Examples of Histogram Tables
The data in the EMPLOYEE table is not distributed evenly with respect to the
primary key because most of the rows in this table are in the EMPNUM equal to
200 range. The SQL/MX optimizer uses the histogram statistics, which divide the
rows into intervals with approximately the same number of rows, to devise plans
for efficient data access. You can use the boundary and row count information in
the histogram tables to specify boundaries for physical partitions of large tables.