Modifying indexes in shapefiles by indexing an attribute

With ArcCatalog, you can add attribute indexes to shapefiles and dBASE tables. An index can improve performance when using the Select By Attributes command in ArcMap to query a column's values or when a column is used to join two tables. Indexes created by ArcCatalog and used by ArcGIS software are different from those created and used by ArcView GIS 3.x—attribute indexes created in ArcCatalog are automatically maintained as values in the column change. Because of this, having too many indexes will decrease performance when the data is edited.

You can also add attribute indexes using the Add Attribute Index tool.

Steps:

1. In ArcCatalog, click the shapefile or dBASE table to which you want to add an attribute index.
2. Click the File menu and click Properties.
3. Click the Index tab.
4. Check an attribute to index its values.
5. Uncheck an attribute to delete its index.
6. Click OK.

Note:

When looking at a table on the Preview tab in ArcCatalog, indexed columns have an asterisk (*) next to their names by default.