storico=# explain select tag_id,valore_tag,data_tag from storico_misure where (data_tag>'2004-05-03' and data_tag <'2004-05-12') and tag_id=37423 ;
Can you please post explain analyze? That includes actual timings.
Looking at the schema, can you try "and tag_id=37423::integer" instead?
enable_hashagg = false enable_hashjoin = false enable_indexscan = true enable_mergejoin = true enable_nestloop = false enable_seqscan = true enable_sort = false enable_tidscan = false
Why do you have these off? AFAIK, 7.4 improved hash aggregates a lot. So you might miss on these in this case.
# - Planner Cost Constants -
#effective_cache_size = 1000 # typically 8KB each
You might set it to something realistic.
And what is your hardware setup? Disks/CPU/RAM?
Just to be sure, you went thr.
http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_conf_e.html and http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html?
HTH
Regards Shridhar
---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings