To speed up XPAC performance, records that are contained in a database range are stored in a cache the first time the range is used. This saves XPAC having to evaluate the range every time it is used.

If the database structure is changed, XPAC is aware that the cache for each range must be re-evaluated and does so the next time the range is used. If you change certain other database information, XPAC may not be aware that the records in the range have changed. For example, if your database range has a constraint which tests the value in a data field, the records in the range may change if the values in the data field are changed. In such cases, it is necessary to tell XPAC that the range must be re-evaluated. This can be done in a number of ways as described below.

Automatic re-evaluation of range

If XPAC is aware that the range needs to be re-evaluated, then it will automatically do this.

Ask about re-evaluation of range

Every time you start XPAC and the first time that you use a database range, a window such as the following will be presented. If you answer Yes, the cache for the range will be used and the range will not be re-evaluated. If you answer No, the cache for the range will be deleted and the range will be re-evaluated.

Manually force re-evaluation of range

If you are not sure whether a range is up to date, or if you change something in the database which you know affects the records in a range (but XPAC doesn't know), you can force the range to be re-evaluated the next time it is used. This is done by deleting the cache for the range. On the Range Selection window, select the relevant database range. On the bottom left of the window, the date of the last record cache for that range is displayed as shown below. To delete the cache for the selected range, click Delete. Alternatively, you can delete the caches for all ranges in the current database by clicking Delete All.