Enabling Statistics

Set the row_counts attribute to exact while creating a table or index.

Note: Statistics for a table or an index must be enabled at the creation time and cannot be enabled or disabled afterward.
The following is an example to create a table named t1 with exact statistics enabled: 
$ tibdg table create row_counts=exact t1 key long

Indexes on a table inherit the value of their table's row_counts setting by default, but can be explicitly configured differently when they are created.

The following is an example to add a secondary index to the table t1 created above with statistics disabled.

Create the index with row_counts set to off: 

$ tibdg index create row_counts=off t1 index2 myfield

See tibdg Table Stats to run a command to view statistics such as row counts or overall table size for a table and all of its indexes.
Note: As there is a minor performance impact associated with enabling statistics on a table or index, you can enable statistics on a table itself to maintain accurate row counts, but explicitly disable statistics on that table's secondary indexes.