So I've recently written a searching addon that does lots of GetItemInfo calls. [insert usual blather about GetItemInfo nil returns, local cache misses, server requests, etc, all well-documented by now] To kludge around these limitations, I keep track if the current search gets any nil returns, and if so, it waits for several seconds (for the presumed server request to finish) and repeats the search. To date, a repeated search has never turned up a second nil return. All good.
The thing is this. For years, the local item cache file would just keep growing. I was looking forward to that behavior, since the number of cache misses would decrease with time. But a while ago, Blizzard made changes to the cache files, and now they seem to max out. Items which have not been displayed for some threshold period of time apparently fall off the end of a least-recently-used cache limit, which (in the case of my addon) triggers the "do over" on the next search involving those items.
And a day or so later, triggers it again. And then again. And again.
Mostly I'm just venting. I don't expect there's any way to change the cache file sizes, say, on a per-computer basis before starting the game client. Addons shouldn't be able to do that programmatically, but I'd love to be able to tell users "do <x> and ease of use goes up".