Question about the read path in cassandra. If a partition/row is in the Memtable and is being actively written to by other clients, will a READ of that partition also have to hit SStables on disk (or in the page cache)? Or can it be serviced entirely from the Memtable?
If you select all columns (e.g., "select * from ....") then I can imagine that cassandra would need to merge whatever columns are in the Memtable with what's in SStables on disk. But if you select a single column (e.g., "select Name from .... where id= ....") and if that column is in the Memtable, I'd hope cassandra could skip checking the disk. Can it do this optimization? Thanks, Don Donald A. Smith | Senior Software Engineer P: 425.201.3900 x 3866 C: (206) 819-5965 F: (646) 443-2333 [email protected]<mailto:[email protected]> [AudienceScience]
