Set up CACHING and NO CACHING for route event tables

Summary

The instructions provided describe how to set up CACHING and NO CACHING for route event tables.

Starting at ArcGIS 8.3 SP3, there is an option to select one of two algorithms for drawing event tables in ArcMap. The choices are CACHING (default) or NO CACHING. These options can improve performance or allow for additional functionality.

CACHING
Under most circumstances, the default method of caching information should be used. When an event table is first displayed in ArcMap, caching stores information about the events. This increases the drawing time the first time the events are displayed since ArcMap has to calculate various statistics and other information, but it allows for faster refreshes when panning or zooming. Aside from the slower first drawing, this means performance is substantially boosted for every subsequent redraw.

NO CACHING
There are two common reasons for selecting the NO CACHING algorithm:

• Editing a very large event table with hundreds of thousands of records

In this case, the initial caching of the event table can take a considerable amount of time. This initial scan can be avoided by using NO CACHING, but the user must be aware that every subsequent pan, zoom or refresh lengthens performance time. When editing very large event tables, it is recommended that both algorithms be tested to see which is best for the particular workflow and underlying database.

• Editing the underlying event table outside of ArcMap, while the same events are being drawn live in ArcMap

When using CACHING, events are not updated in ArcMap when the screen is refreshed, so newly added events are not displayed. If caching is off, ArcMap has to read the event table from scratch every time it refreshes. Therefore, if a new record is added and saved in the outside table, ArcMap must refresh the display to draw the new event. Since caching is not being used, this means all refreshes are slower; however, some organizations need to edit the event table outside of ArcMap and see the changes live in ArcMap.

Procedure

1. Close ArcMap.
2. Download the appropriate script for the version of ArcGIS in use, either the Display Events Without Caching Script, or the Display Events With Caching Script.
3. Unzip the ZIP file and double-click the REG file in Windows Explorer. If prompted, click Yes or OK.
   The next time ArcMap starts, events are displayed using the method selected.