Caching within a request

dev
1

I stumbled upon this Lucee Recipe earlier.

At first I was baffled on why I’d want to cache a query within the current request. The only thing I can think of off the top of my head is if the query was inside a loop.

Are there oher scenarios where cachedWithin="request" would come in handy?

Cache a Query for the current request

Perhaps you’re familiar with the “cachedwithin” attribute of the tag [tag-query], which is normally used as follows:

<cfquery cachedWithin="#createTimeSpan(0,0,0,1)#"> select * from whatever where whatsoever='#whatsoever#' 
</cfquery>

This caches the query result for ALL users for one second. This is sometimes used to cache a query for the current request because usually most requests are completed in less than a second.

The problem is that this cache applies to all requests and that’s more complicated for Lucee, meaning unnecessary overhead on the system.

Request query caching is a simple solution to this problem. Replace the timespan defined in the “cachedWithin” attribute with the value “request”:

<cfquery cachedWithin="request"> select * from whatever where whatsoever='#whatsoever#' </cfquery>

Then the query is cached for only the current request, independent of how long the request takes!

2

Depends how complex your code base is, applications often have widgets or sub views that might render separately but also in an initial request, these might share data / queries, for performance it might make sense to only hit the database once for the same request

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