RE: index
UPDATE STATISTICS? Just a guess.... ;-)
G
hello group
this is my select :
distretto and numero is not primary key
select * from tt_master where distretto=0444 and numero=00563921
----------------------------------------------------------------------------
-------------------i have created the this index :
CREATE index ttmaster3 ON tt_master
(
distretto,numero
)
in dbdati3
result:
index name Owner Type Cluster Columns
ttmaster3 olbb dupls No distretto
numero
----------------------------------------------------------------------------
--
when i do the explain plain result this is:
QUERY:
------
select * from tt_master where distretto=0444 and numero=00563921
Estimated Cost: 36484
Estimated # of Rows Returned: 1
1) olbb.tt_master: SEQUENTIAL SCAN
Filters: (olbb.tt_master.distretto = 444 AND olbb.tt_master.numero = 563921
)
why ?????
tanks
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If both fields are defined as char use quotes around values.
Otherwise you are forcing conversion for every row.
(BTW. Oracle for example refuses to execute a statement like that...)
HTH
Michael
Roff, Geoff wrote:
>UPDATE STATISTICS? Just a guess.... ;-)>
>G
>
>hello group
>
>this is my select :
>distretto and numero is not primary key
>
>select * from tt_master where distretto=0444 and numero=00563921
>----------------------------------------------------------------------------
>------------------->i have created the this index :
>
>CREATE index ttmaster3 ON tt_master
>(
>distretto,>numero
>)
>in dbdati3
>
>result:
>
>index name Owner Type Cluster Columns
>
>ttmaster3 olbb dupls No distretto
> numero
>
>----------------------------------------------------------------------------
>--
>when i do the explain plain result this is:
>
>QUERY:
>------
>select * from tt_master where distretto=0444 and numero=00563921>
>Estimated Cost: 36484
>Estimated # of Rows Returned: 1
>
>1) olbb.tt_master: SEQUENTIAL SCAN
>
> Filters: (olbb.tt_master.distretto = 444 AND olbb.tt_master.numero = 563921
>)
>
>
>why ?????
>
>
>tanks
>
>**********************************************************************************
>This message is sent in strict confidence for the addressee only. It may
>contain legally privileged information. The contents are not to be disclosed
>to anyone other than the addressee. Unauthorised recipients are requested
>to preserve this confidentiality and to advise the sender immediately of any
>error in transmission.
>This footnote also confirms that this email message has been swept for the
>presence of computer viruses, however we cannot guarantee that this message
>is free from such problems.
>**********************************************************************************
>
>