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:tgl@xxxxxxxxxxxxx] > Enviada em: quinta-feira, 11 de janeiro de 2007 16:31 > Para: carlos.reimer@xxxxxxxxxxxxx > Cc: pgsql-performance@xxxxxxxxxxxxxx > Assunto: Re: [PERFORM] Improving SQL performance > > > "Carlos H. Reimer" <carlos.reimer@xxxxxxxxxxxxx> 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 > >