Good answer Oleksandr, But I think the data is inserted in the Memtable already in the right order. At least the datastax academy videos say so. But it shouldn't make any difference anyhow.
Kind regards, Lucas Benevides 2017-12-08 5:41 GMT-02:00 Oleksandr Shulgin <oleksandr.shul...@zalando.de>: > On Fri, Dec 8, 2017 at 3:05 AM, Eunsu Kim <eunsu.bil...@gmail.com> wrote: > >> There is a table with a timestamp as a cluster key and sorted by ASC for >> the column. >> >> Is it better to insert by the time order when inserting data into this >> table for insertion performance? Or does it matter? >> > > The writes hit memory tables first, so from this perspective it shouldn't > matter. > > Later the memory tables are sorted according to the partition and > clustering key and are flushed to disk in this order, forming the SSTable > files. The difference in performance you might experience upon reading the > data, depending on compaction strategy you choose. For time-series data > with TTL there is good chance that TimeWindowCompactionStrategy is > appropriate, given you mostly write with approx. monotonically increasing > timestamps. This helps organizing the data files for faster reads and > really cheap removal of expired data: the whole file can be just dropped by > compaction process once all records in it expire. > > Regards, > -- > Oleksandr "Alex" Shulgin | Database Engineer | Zalando SE | Tel: +49 176 > 127-59-707 <+49%20176%2012759707> > >
