W dniu 30.12.2011 17:01, Matteo Sgalaberni pisze: > Hi, Hello, > I have a two tables that are partitioned by month. > > I have different results for the same query (query A/query B), the only thing that differ from A and B is the customer id. Not only: > Query A: > > SELECT sms.id AS id_sms > > FROM > sms_messaggio AS sms, > sms_messaggio_dlr AS dlr > WHERE sms.id = dlr.id_sms_messaggio > AND sms.timestamp_todeliver >= '1/3/2010'::timestamp > AND sms.timestamp_todeliver < '30/4/2010'::timestamp > AND dlr.timestamp_todeliver >= '1/3/2010'::timestamp > AND dlr.timestamp_todeliver < '30/4/2010'::timestamp > AND sms.id_cliente = '13' > ORDER BY dlr.timestamp_todeliver DESC LIMIT 50; ^^^^^^^ > Query B: > EXPLAIN ANALYZE SELECT sms.id AS id_sms, > dlr.msisdn, > to_char(dlr.timestamp_stato,'DD/MM/YYYY HH24:MI:SS') AS timestamp_stato, > dlr.stato, > dlr.id AS id_dlr, > dlr.numero_pdu, > dlr.costo_cli > FROM > sms_messaggio AS sms, > sms_messaggio_dlr AS dlr > WHERE sms.id = dlr.id_sms_messaggio > AND sms.timestamp_todeliver >= '1/3/2010'::timestamp > AND sms.timestamp_todeliver < '30/4/2010'::timestamp > AND dlr.timestamp_todeliver >= '1/3/2010'::timestamp > AND dlr.timestamp_todeliver < '30/4/2010'::timestamp > AND sms.id_cliente = '7' > ORDER BY dlr.timestamp_todeliver ASC LIMIT 50; ^^^^^ > I'm using pg 9.1 > > Can someone explain me why the planner do this? Those queries are diffrent. Regards. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance