Does anyone know of any documentation on this function, "compile all classes" on the Apex Classes page? I'm finding nothing on help.salesforce.com or elsewhere.
(UPDATE regarding desire to automate at bottom of Question)
I'm being told by a less-than-trustworthy source (the maker of an SF plugin we use) that this is supposed to be used ANY TIME you upgrade an SF plugin. That alone is an overstatement i'm sure, and they are using it to stave off complaints about 1-2 minute Apex routines (processing a single record).
Any insights would be helpful. I'm not sure I even recall seeing this option in my 6+ years with Salesforce products.
UPDATE: What I'd like is to be able to automatically run the "Compile All Classes" function daily at 6:45am. Being that I'm told by another source (SF Support) that it's declarative, that apparently translates into "it cannot be scheduled". I'd like to believe you can create a class (trigger?) which could be scheduled to run the function on a daily (possibly twice daily) basis. Once again, this is because the maker of a plugin to Salesforce believes this will fix our speed problems in THEIR product).
Scheduling code to run is "easy enough" (console or GUI) but I apparently don't have something that CAN be scheduled to actually run this function.
I am in the midst of testing this, manually running it daily, to see if the performance increase happens... given that this all stems from a Salesforce "Pre-Compile" feature (likely what's being described somewhat in comments below), and that it's now fixed, in our Org, for SF standard objects, but it's NOT doing anything for third party plugins, the hope is that this suggestion to auto run "Compile" each day will solve things.
UPDATE 2: Salesforce support is "investigating" writing the code necessary to schedule Compile All Classes. If(/when?) I receive this, I will post it as an answer here. (noted on 2017-03-31)