--- In firebird-support@yahoogroups.com, "flashjobs" <flashjobs@...>
wrote:

>
> Hello all
>
> I have a problem that the query is very slow. Can anybody help?
>
> Thanks
>
> Shinelal
>
> SELECT PRODUCTCODE
> , PRODUCTNAME
> , PRODUCTCOSTLOCALCURRENCY
> , PRODUCTCOSTORGCURRENCY
> , PRODUCTISBN
> , PRODUCTBARCODE
> , PRODUCTSTOCKUPDATE
> , CURRENCYNAME
> , P.CURRENCYCODE
> , TAXDESCRIPTION
> , TAXPERCENTAGE
> , PRODUCTPUBLISHINGYEAR
> , SUPPLIERNAME
> , CURRENCYCONVERTRATE
> , CURRENCYLOCALASREF
> FROM (((PRODUCTMASTER P
> LEFT OUTER JOIN CURRENCYMASTER C ON C.CURRENCYCODE = P.CURRENCYCODE)
> LEFT OUTER JOIN TAXMASTER T ON T.TAXCODE = P.TAXCODE)
> LEFT OUTER JOIN SUPPLIERMASTER S ON S.SUPPLIERCODE=P.PUBLISHERCODE)
> WHERE PRODUCTSTOCKUPDATE = 'Y' AND
> ((PRODUCTCODE IN (SELECT PRODUCTCODE FROM STOCKMASTER WHERE
> OUTLETCODE=?OUTLET
> AND BRANCHCODE=?BRANCH )or 2=0) OR
> PRODUCTCODE NOT IN(SELECT PRODUCTCODE FROM STOCKMASTER))
>

We don't know your database, what table does each field belong to?

My guesses

-> 2=0

This will be evaluated for every record

-> NOT IN

By definition, not in will be expensive.

Adam