musicbrainz_db_raw_rc1=> explain analyze SELECT vote, count(vote) AS count FROM vote WHERE editor = '95678' GROUP BY vote;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------
HashAggregate (cost=150879.93..150879.94 rows=1 width=2) (actual time=1508.100..1508.103 rows=3 loops=1)
-> Seq Scan on vote (cost=0.00..150614.40 rows=53105 width=2) (actual time=689.430..1443.017 rows=59721 loops=1)
Filter: (editor = 95678)
Total runtime: 1508.229 ms
(4 rows)

musicbrainz_db_raw_rc1=> \d vote
Table "musicbrainz.vote"
Column | Type | Modifiers
-------------------------------------------------------------------------------------
id | integer | not null default nextval('vote_id_seq'::regclass)
editor | integer | not null
edit | integer | not null
vote | smallint | not null
vote_time | timestamp with time zone | default now()
superseded | boolean | not null default false
Indexes:
"vote_pkey" PRIMARY KEY, btree (id)
"vote_idx_edit" btree (edit)
Foreign-key constraints:
"vote_fk_edit" FOREIGN KEY (edit) REFERENCES edit(id)

musicbrainz_db_raw_rc1=> create index vote_idx_editor on vote (editor);
CREATE INDEX
musicbrainz_db_raw_rc1=> explain analyze SELECT vote, count(vote) AS count FROM vote WHERE editor = '95678' GROUP BY vote;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------------
HashAggregate (cost=59158.15..59158.16 rows=1 width=2) (actual time=145.156..145.159 rows=3 loops=1)
-> Bitmap Heap Scan on vote (cost=996.65..58892.62 rows=53105 width=2) (actual time=9.651..81.134 rows=59721 loops=1)
Recheck Cond: (editor = 95678)
-> Bitmap Index Scan on vote_idx_editor (cost=0.00..983.37 rows=53105 width=0) (actual time=8.524..8.524 rows=59721 loops=1)
Index Cond: (editor = 95678)
Total runtime: 145.235 ms
(6 rows)