The following bug has been logged online:
Bug reference: 1122
Logged by: P Buder
Email address: [EMAIL PROTECTED]
PostgreSQL version: 7.3.5
Operating system: Debian Linux
Description: limit 1 doing a sequential scan
Details:
I am actually running 7.3.6 but that isn't available on the drop down menu
to report a bug so there is another bug :)
When I do a select * from table limit 1
Postgresql does a sequential scan on the whole table. It should just pick
one row and be done with it. The table has been analyzed but that shouldn't
matter. This particular table has 4.3 million rows. Here is the explain
select.
book=# explain select * from imdata limit 1;
QUERY PLAN
----------------------------------------------------------------------
Limit (cost=0.00..55.85 rows=1 width=152)
-> Seq Scan on imdata (cost=0.00..269569.27 rows=4827 width=152)
(2 rows)
---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match
