During our many years of examining applications for performance problems, @DbLookups have popped up more often than we can count. The usefulness of this functionality is undeniable, but so too can be the slowdowns incurred when an application form needs several lookups to large views. Even worse, these @Db formulas often execute even when the document is opened in Read mode. Note that for web applications, drop‑down lists will not execute their @Db formulas in Read mode, but for Notes client applications, they will (at least by default).
The following steps can dramatically improve the performance of @Db formulas in keyword fields, regardless of whether the application is for web browsers or Notes clients:
1. Create a keyword drop‑down field
2. Use
PostModeChange
event to refresh the keyword list3. Create a view for the lookup
The following sections describe these three steps in detail.