Andreas Kretschmer <andreas@a-kretschmer.de> wrote on 03/28/2019 07:28:53 AM:
> > > > Ummm... Will it use an index (a BTree index)? > > > > test=# explain select * from emp where ename = 'aaa'; > QUERY PLAN > ----------------------------------------------------- > Seq Scan on emp (cost=0.00..25.88 rows=6 width=36) > Filter: (ename = 'aaa'::citext) > (2 rows) > > test=*# set enable_seqscan to off; > SET > test=*# explain select * from emp where ename = 'aaa'; > QUERY PLAN > ------------------------------------------------------------------------ > Seq Scan on emp (cost=10000000000.00..10000000025.88 rows=6 width=36) > Filter: (ename = 'aaa'::citext) > (2 rows) > > test=*# create index emp_ename on emp(ename); > CREATE INDEX > test=*# explain select * from emp where ename = 'aaa'; > QUERY PLAN > ---------------------------------------------------------------------- > Index Scan using emp_ename on emp (cost=0.13..8.14 rows=1 width=36) > Index Cond: (ename = 'aaa'::citext) > (2 rows)
I used citext heavily in a past project and was quite happy with it. It was never a source of performance issues.
