I have grabbed one day slow query log and analyzed it by pgfouine, to my surprise, the slowest query is just a simple select statement:
*select diggcontent_data_message.thing_id, diggcontent_data_message.KEY, diggcontent_data_message.value, diggcontent_data_message.kind FROM diggcontent_data_message WHERE diggcontent_data_message.thing_id = 3570882;* where thing_id is the primary key, guess how long it takes? 754.61 seconds!! I tried explain analyze it and below is the result, which is very fast: * * * explain analyze select diggcontent_data_message.thing_id, diggcontent_data_message.KEY, diggcontent_data_message.value, diggcontent_data_message.kind FROM diggcontent_data_message WHERE diggcontent_data_message.thing_id = 3570882; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------- Index Scan using idx_thing_id_diggcontent_data_message on diggcontent_data_message (cost=0.00..15.34 rows=32 width=51) (actual time=0.080..0.096 rows=8 loops=1) Index Cond: (thing_id = 3570882) Total runtime: 0.115 ms (3 rows) * so I wonder could this simple select is innocent and affected badly by other queries? how could I find those queries that really slow down the database? thanks!
