>>... for all records in the current block only (as far as I know) ...
>
>What do you mean by "current block"?

The cacheblock in the client the record resides in where the RLock() is performed upon.

RLock() just forces the server to provide for the most current data for the record, but the server can only throw data at block level. And, it won't throw the whole file obviously. Further, nothing tells the client that it must collect a fresh block when it needs a record when the current block overflows to the next (skip etc.) i.e. the RLock() doesn't provide for that.

Therefor Set Refresh is a tricky thing, because it will only refresh the cacheblocks at the given interval, and looping through a file of 1M records, will refresh the coindentally present (actual) block only at the interval, say once per sec = once per 2,000 records.
It's all rather hard to test because you have to know what's in the cache, though this can obviously be forced. A sniffer will do the rest.