Index Item (Coverage)
Creates an attribute index to increase access speed to the specified item during query operations.
Indexed items speed up selection operations of large INFO files.
Item indexes are preserved when the coverage or INFO table is copied to a new location.
Items must be indexed to support native mode reselects against external database management system (DBMS) tables.
An index file becomes outdated if the following commands are used on the INFO table: Calculate Field, Update, Build, or Clean. Attempting to use the outdated index will cause the following message to be generated: "Index file is obsolete." If you receive this message, rebuild the index file and continue.
The name of the INFO table containing the item to be indexed
The name of the item to be indexed
The following stand-alone script demonstrates how to index an item in a coverage, and then select features using the indexed item.
# Name: IndexItem_Example.py # Description: Indexes an item then uses that item to select features. # Requirements: ArcInfo Workstation # Author: ESRI # Import system modules import arcpy from arcpy import env # Set environment settings env.workspace = "C:/data" # Set local variables inInfoTable = "stream/arc" indexItem = "STRM_ORD" inCover = "stream" outCover = "C:/output/lowerstreams" infoExpress = ["RESELECT STRM_ORD > 3"] # Execute IndexItem arcpy.IndexItem_arc(inInfoTable, indexItem) arcpy.Reselect_arc(inCover, outCover, infoExpress)