title: psql: SELECT not showing results correctly in psql client
body: <p>OK, I have a Postgres table with a bunch of data. In particular, when I do a SELECT query with a condition on the <code>id</code>, it finds the result fine; but if I do it on the <code>person_id</code> column (which has a joint index between <code>person_id</code> and <code>course_id</code>), then it finds nothing. Specifically, it seems to fail to retrieve results based on the <code>person_id</code>; 10482 doesn't result in anything, but 10484 does.</p>
  
  <p>What might be going on?</p>
  
  <p>Transcript:</p>
  
  <pre><code>CS198=# select * from enrollments where id=19513;
  select * from enrollments where id=19513;
    id   | person_id | course_id | position | seniority
  -------+-----------+-----------+----------+-----------
   19513 |     10482 |       177 | Student  |         0
  (1 row)
  
  Time: 0.345 ms
  CS198=# select * from enrollments where id=19513 and person_id=10482;
  select * from enrollments where id=19513 and person_id=10482;
    id   | person_id | course_id | position | seniority
  -------+-----------+-----------+----------+-----------
   19513 |     10482 |       177 | Student  |         0
  (1 row)
  
  Time: 0.370 ms
  CS198=# select * from enrollments where person_id=10482;
  select * from enrollments where person_id=10482;
  Time: 0.369 ms
  </code></pre>
  
  <p>Note that in the last case... no results displayed. wtf?</p>
  
  <p>Thanks in advance! I'm puzzled :P</p>
  
  <p>EDIT: Strangely enough, as in the transcript above it isn't reporting that there is 0 rows of results; it just doesn't print anything at all. Normally when there are no results it would tell me that explicitly; maybe my Postgres configuration is messed up?</p>
  
  <pre><code>\timing on
  \setenv LESS -imx4F
  \x auto
  
  \set HISTCONTROL ignorespace
  \set HISTFILE ~/.psql_history- :DBNAME
  \set HISTSIZE 20000
  
  \pset null '[NULL]'
  </code></pre>
  
  <p>EDIT 2: Using Induction, a different SQL client instead of <code>psql</code>, it does show the missing results; so the real question is: what might be the problem with my <code>psql</code> configuration?</p>