Fix Version/s: 2.1 beta1
Changing the row cache to a row+filter cache would make it much more useful. We currently have to warn against using the row cache with wide rows, where the read pattern is typically a peek at the head, but this usecase would be perfect supported by a cache that stored only columns matching the filter.
- (copout) Cache a single filter per row, and leave the cache key as is
- Cache a list of filters per row, leaving the cache key as is: this is likely to have some gotchas for weird usage patterns, and it requires the list overheard
- Change the cache key to "rowkey+filterid": basically ideal, but you need a secondary index to lookup cache entries by rowkey so that you can keep them in sync with the memtable