> where jualid is not null > and extract(year from tanggal)='2013')
> But the problem is : when i change the where clause to : > > where jualid is not null or returjualid is not null > and extract(year from tanggal)='2013') > > (there is additional or returjualid is not null,) the query needs > 56 second to display the result.
Before worrying about the run time, I would worry about whether you are getting the results you expect. That will be interpreted as:
where jualid is not null
or (returjualid is not null and extract(year from tanggal) = '2013')
... not:
where (jualid is not null or returjualid is not null) and extract(year from tanggal) = '2013' AND has higher priority than OR; so if you want to limit by year from tanggal even when jualid is not null, you must use parentheses.
