testdb=# \dt+ azjunk7
                      List of relations
 Schema |  Name   | Type  |  Owner   |  Size   | Description
--------+---------+-------+----------+---------+-------------
 public | azjunk7 | table | aardvark | 1116 MB |
(1 row)

testdb=# select count(*) from azjunk7;
  count
----------
 10000000
(1 row)

testdb=# explain analyze select * from azjunk7 where position('erix' in txt) > 0;
                                                    QUERY PLAN
-------------------------------------------------------------------------------------------------------------------
 Seq Scan on azjunk7  (cost=0.00..292858.04 rows=3333334 width=81) (actual time=9.515..5075.596 rows=1008 loops=1)
   Filter: ("position"(txt, 'erix'::text) > 0)
   Rows Removed by Filter: 9998992
 Total runtime: 5075.836 ms
(4 rows)

Time: 5076.568 ms

-- OK. 5 seconds.

testdb=# copy (select * from azjunk7) to '/tmp/rawdump';
COPY 10000000
Time: 6538.458 ms
testdb=# \q

#
#  bash shell:
#

$ time grep -c 'erix' /tmp/rawdump
1008
real    0m0.875s
user    0m0.683s
sys     0m0.161s