All;
Can anyone please help with the tuning of this query?
With 77000 rows in the operator_messages database the query is taking almost
15 seconds to return. Preference woul dbe under 5 seconds if possible.
System load on a dual processor P3 with 1.5GB of memory remains under .4
during the query.
The query and explain are noted below as well as description of the tables;
Note both ANALYZE and VACUUM have been run numerous times.
any help would be appreciated. -Kev
virgin=# explain SELECT opr.msg_id, opr.status, opc.std_time
virgin-# FROM op_msg_folder opc, operator_messages opr
virgin-# WHERE opr.username = 'khp'
virgin-# AND opr.foldername = 'inbox'
virgin-# and opr.msg_id = opc.msg_id;
NOTICE: QUERY PLAN:
Merge Join (cost=25037.29..27675.47 rows=47958 width=54) -> Index Scan using opmf_i on op_msg_folder opc
(cost=0.00..1797.37
rows=48579 width=32) -> Sort (cost=25037.29..25037.29 rows=47958 width=22) -> Seq Scan on operator_messages
opr (cost=0.00..20722.26
rows=47958 width=22)
virgin=# \d operator_messages Table "operator_messages" Column | Type | Modifiers
------------+--------------+-----------msg_id | numeric |username | text |foldername | text
|status | character(1) |
Indexes: op_msgs_i, opr_msgs_foldername_i, opr_msgs_username_i
virgin=# \d op_msgs_i
Index "op_msgs_i"Column | Type
--------+---------msg_id | numeric
btree
virgin=# \d opr_msgs_foldername_i
Index "opr_msgs_foldername_i" Column | Type
------------+------foldername | text
btree
virgin=# \d opr_msgs_username_i
Index "opr_msgs_username_i" Column | Type
----------+------username | text
btree
virgin=# \d op_msg_folder Table "op_msg_folder" Column | Type | Modifiers
----------------+--------------+-----------msg_id | numeric |status | character(1) |std_time
|text |julian_time | text |smi | character(3) |description | text |type
| text |flight | text |tail | text |dep_station | text
|dest_station | text |op_description | text |
Unique keys: opmf_i
virgin=# \d opmf_i; Index "opmf_i"Column | Type
--------+---------msg_id | numeric
unique btree
