Thanks for the response! I could understand that being the case if the Cassandra cluster is not loaded. Splitting the work across multiple nodes would obviously make the query faster.
But if this was just a single node, shouldn't one IN query be faster than multiple due to the fact that, if I understand correctly, Cassandra should need to do less work? thanks in advance, Gareth On Wed, Feb 21, 2018 at 7:27 AM, Rahul Singh <rahul.xavier.si...@gmail.com> wrote: > That depends on the driver you use but separate queries asynchronously > around the cluster would be faster. > > > -- > Rahul Singh > rahul.si...@anant.us > > Anant Corporation > > On Feb 20, 2018, 6:48 PM -0500, Eric Stevens <migh...@gmail.com>, wrote: > > Someone can correct me if I'm wrong, but I believe if you do a large IN() on > a single partition's cluster keys, all the reads are going to be served from > a single replica. Compared to many concurrent individual equal statements > you can get the performance gain of leaning on several replicas for > parallelism. > > On Tue, Feb 20, 2018 at 11:43 AM Gareth Collins <gareth.o.coll...@gmail.com> > wrote: >> >> Hello, >> >> When querying large wide rows for multiple specific values is it >> better to do separate queries for each value...or do it with one query >> and an "IN"? I am using Cassandra 2.1.14 >> >> I am asking because I had changed my app to use 'IN' queries and it >> **appears** to be slower rather than faster. I had assumed that the >> "IN" query should be faster...as I assumed it only needs to go down >> the read path once (i.e. row cache -> memtable -> key cache -> bloom >> filter -> index summary -> index -> compaction -> sstable) rather than >> once for each entry? Or are there some additional caveats that I >> should be aware of for 'IN' query performance (e.g. ordering of 'IN' >> query entries, closeness of 'IN' query values in the SSTable etc.)? >> >> thanks in advance, >> Gareth Collins >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org >> For additional commands, e-mail: user-h...@cassandra.apache.org >> > --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org For additional commands, e-mail: user-h...@cassandra.apache.org
