>-----Messaggio originale----- >Da: pgsql-general-owner@xxxxxxxxxxxxxx [mailto:pgsql-general-owner@xxxxxxxxxxxxxx] Per conto di Adrian Klaver >Inviato: giovedì 12 febbraio 2009 17.28 >A: pgsql-general@xxxxxxxxxxxxxx >Cc: Paolo Saudin >Oggetto: Re: How to check if 2 series of data are equal >On Thursday 12 February 2009 12:06:41 am Paolo Saudin wrote: >> Hi, >> >> I have 14 tables filled with meteorological data, one record per parameter >> per hour. The id field holds the parameter type (1=temperature, 2=humidity >> ...) My problem is that for short periods (maybe one week, one month) there >> are two stations with the same data, I mean the temperature of table1 is >> equal to the humidity of table3. I need to discover those cases. >Before I can start to answer this I need some clarification. How can temperature >and humidity be the same data? Can be the same data ( and it is ) because of errors in the remote stations configurations. The Stations and parameters IDs were mixed up resulting in same data in different tables ... >> >> I could pick one record in the first station and then compare it with the >> ones in the other tables for all the parameters at that particular date. If >> two records are equals (it probably happens) I must then check the next one >> in the timeserie. If the second record is equal too, then probably the two >> series may be equals and I must raise an alert from my application. Is >> there a better and faster way to perform such a check ? >> >> -- tables >> CREATE TABLE table1 >> ( >> fulldate timestamp, >> id smallint NOT NULL, >> meanvalue real >> ) WITH (OIDS=FALSE); >> --..................... >> --..................... >> CREATE TABLE table14 >> ( >> fulldate timestamp, >> id smallint NOT NULL, >> meanvalue real >> ) WITH (OIDS=FALSE); >> -- >> -- inserts >> insert into table1(select >> ('2009-01-01'::timestamp + interval '1 hour' * s.a)::timestamp, >> 1::smallint, round(cast(random() as numeric), 1)::real >> from generate_series(0,1000) as s(a) >> ); >> -- >> insert into table2(select >> ('2009-01-01'::timestamp + interval '1 hour' * s.a)::timestamp, >> 1::smallint, round(cast(random() as numeric), 1)::real >> from generate_series(0,1000) as s(a) >> ); >> -- >> -- same data as table 1 -- MUST BE FOUND BY THE CKECK ROUTINE >> insert into table3(select fulldate, id, meanvalue from table1); >> >> >> Thank in advance, >> Paolo Saudin >-- >Adrian Klaver >aklaver@xxxxxxxxxxx >-- >Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) >To make changes to your subscription: >http://www.postgresql.org/mailpref/pgsql-general -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
