When adding a new custom table to the index or editing an existing one, you have the following options:

 

•Custom table - custom table to be indexed.

•Where condition - WHERE clause of the queries run against the custom table when building the index. This can be used to limit which records (rows) in the table should be included.

 
More resources can be found at:

 

•Developer's Guide -> Modules -> Smart search -> Overview

•Developer's Guide -> Modules -> Smart search -> Managing indexes -> Defining custom tables index content