Did you benchmark these two options: 1) Select with IN
2) Select all words and filter in application Mohammed From: Philo Yang [mailto:ud1...@gmail.com] Sent: Thursday, July 31, 2014 10:45 AM To: user@cassandra.apache.org Subject: select many rows one time or select many times? Hi all, I have a cluster of 2.0.6 and one of my tables is like this: CREATE TABLE word ( user text, word text, flag double, PRIMARY KEY (user, word) ) each "user" has about 10000 "word" per node. I have a requirement of selecting all rows where user='someuser' and word is in a large set whose size is about 1000 . In C* document, it is not recommended to use "select ... in" just like: select from word where user='someuser' and word in ('a','b','aa','ab',...) So now I select all rows where user='someuser' and filtrate them via client rather than via C*. Of course, I use Datastax Java Driver to page the resultset by setFetchSize(1000). Is it the best way? I found the system's load is high because of large range query, should I change to select for only one row each time and select 1000 times? just like: select from word where user='someuser' and word = 'a'; select from word where user='someuser' and word = 'b'; select from word where user='someuser' and word = 'c'; ..... Which method will cause lower pressure on Cassandra cluster? Thanks, Philo Yang
