Understanding the iMIS cache and how it affects performance

The cache is a temporary storage where iMIS keeps recently or frequently accessed data. Instead of recalculating or pulling from the database every time, iMIS pulls from the cache, which is much faster. The cached data improves performance and responsiveness of iMIS for all users by reducing repetitive database calls and speeding up page loads.

The Purge System Cache button

The Purge System Cache button (Settings > About iMIS) clears the cache across all of iMIS, meaning all users lose their cached data. After purging, iMIS must rebuild the cache by querying the database again, which causes performance slowdowns until it stabilizes.

Purging the cache can negatively affect performance

Right after purging, iMIS must rebuild the cache from scratch, making pages and queries slower until it is rebuilt. Because this is a system-wide cache, every user feels the slowdown. Caches usually refresh automatically when data changes, so manual purging is rarely needed.

Understanding when to and not to purge the cache

Review the following to understand when to and not to purge the cache.

Note: With the exception of SQL scripts run outside of iMIS, you should not need to purge the cache for normal processes to work. If you find that purging is required for something to work, it may indicate that additional iMIS development is required in that area. Contact ASI Support for assistance.

Do not purge the cache. . .	Do purge the cache . . .
Right after publishing content. Doing so will cause iMIS to significantly slow down. If only one page or query looks wrong. Instead, try troubleshooting there (permissions, IQA change, browser cache). When users report general slowness. Purging will make iMIS slower and will not fix performance issues caused by hardware, large queries, or network conditions. When viewing a single IQA or dashboard. Cached results are often refreshed automatically; try running the IQA again or editing/saving it to trigger an update. To force design changes to appear. Many page builder/design updates show without a purge. Check browser cache or security permissions first. During peak business hours. All users will be slowed down while the cache rebuilds.	When instructed by ASI Support. Sometimes support staff will specifically request a cache purge during troubleshooting. If multiple users consistently see outdated information. For example, membership status, pricing, or contact data not refreshing for more than one staff user. If an issue is isolated to a single staff user, the issue is probably not the cache.

Do not purge the cache. . .

Do purge the cache . . .

Right after publishing content. Doing so will cause iMIS to significantly slow down.
If only one page or query looks wrong. Instead, try troubleshooting there (permissions, IQA change, browser cache).
When users report general slowness. Purging will make iMIS slower and will not fix performance issues caused by hardware, large queries, or network conditions.
When viewing a single IQA or dashboard. Cached results are often refreshed automatically; try running the IQA again or editing/saving it to trigger an update.
To force design changes to appear. Many page builder/design updates show without a purge. Check browser cache or security permissions first.
During peak business hours. All users will be slowed down while the cache rebuilds.

When instructed by ASI Support. Sometimes support staff will specifically request a cache purge during troubleshooting.
If multiple users consistently see outdated information. For example, membership status, pricing, or contact data not refreshing for more than one staff user. If an issue is isolated to a single staff user, the issue is probably not the cache.

Best practices

Time it wisely - If you must purge, do it during off-peak hours when the fewest users are logged in.
Communicate with users - Let your team know when you plan to purge cache so they understand any temporary slowness.
Monitor after purging - Watch performance and confirm that the issue you were targeting is resolved.
Do not confuse it with browser cache - Users can clear their own browser cache if they see display glitches — this is different from purging the iMIS cache.