Generally indexes on binary fields true/false male/female are not terrible effective.
On Tue, Jan 28, 2014 at 12:40 PM, Jimmy Lin <y2klyf+w...@gmail.com> wrote: > I have a simple column family like the following > > create table people( > company_id text, > employee_id text, > gender text, > primary key(company_id, employee_id) > ); > > if I want to find out all the "male" employee given a company id, I can do > > 1/ > select * from people where company_id=xxxx' > and loop through the result efficiently to pick the employee who has > gender column value equal to "male" > > 2/ > add a seconday index > create index gender_index on people(gender) > select * from people where company_id='xxx' and gender='male' > > > I though #2 seems more appropriate, but I also thought the secondary index > is helping only locating the primary row key, with the select clause in #2, > is it more efficient than #1 where application responsible loop through the > result and filter the right content? > > ( > It totally make sense if I only need to find out all the male employee(and > not within a company) by using > select * from people where gender='male" > ) > > thanks >
