Hi, Carlos,
Wouldn't it be better if you used INT in 'codcep' in both tables (as
CEP/ZIP numbers are [0-9]{8})? Casting as Tom Lane suggested is also a
good alternative, yet I think it'd be much better if you used int in
both columns.
Regards,
Cesar
Let's see the query:
SELECT ENDE.* , DEND.DESEND, DEND.USOEND, DEND.DUPEND,
to_char('F') as NOVO,
LOG.TIPLOG
FROM TT_END ENDE LEFT OUTER JOIN TD_END DEND ON DEND.CODTAB =
ENDE.TIPEND
LEFT OUTER JOIN TT_LOG LOG ON LOG.CODCEP =
ENDE.CODCEP||CODLOG
WHERE ENDE.FILCLI = '001'
AND ENDE.CODCLI = ' 19475';
Carlos H. Reimer wrote:
Yes, I do have an index on tt_log.codcep.
Indexes I´ve on both tables:
tt_end
Indexes:
"pk_end" PRIMARY KEY, btree (filcli, codcli, codfil, numend)
"ak_end_numdoc" UNIQUE, btree (numdoc)
"i_fk_end_darc" btree (codarc, tiparc)
"i_fk_end_dend" btree (tipend)
"i_fk_end_dfil" btree (codfil)
"i_fk_end_dreg" btree (regiao)
"i_fk_end_mun" btree (codcid)
tt_log
Indexes:
"i_fk_log_bai" btree (codbai)
"i_lc_log_codcep" btree (codcep)
Any clue?
Thanks!
Reimer
-----Mensagem original-----
De: Tom Lane [mailto:[EMAIL PROTECTED]
Enviada em: quinta-feira, 11 de janeiro de 2007 16:31
Para: [EMAIL PROTECTED]
Cc: pgsql-performance@postgresql.org
Assunto: Re: [PERFORM] Improving SQL performance
"Carlos H. Reimer" <[EMAIL PROTECTED]> writes:
I know that the problem with the following SQL is the "LOG.CODCEP =
ENDE.CODCEP||CODLOG" condition, but what can I
do to improve the performance?
Seems the problem is not using an index for tt_log. Do you have an
index on tt_log.codcep? If so, maybe you need to cast the result of
the concatenation to char(8) to get it to use the index.
regards, tom lane
---------------------------(end of broadcast)---------------------------
TIP 6: explain analyze is your friend
---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
