Query Excution Process- pros and cons
Q1>Should I apply filter in sequence(based on primarykey,not null,comparision,between clause) ?
-How to apply filter in correct format,and SQL server internally execute it.
Q2>Should I use 'is not Null' to be put at the last or first?
Q3>Should I use 'between clause' rather than relation operator i.e(empid>10 and empid<200)
Q4>Does filters of sequence has any impact on the query execution process
table1[pkey1,col1,col2,col3] -->pkey is pkey1
table2[pkey2,pkey1,col11,col12,col13]--->pkey is pkey2, and pkey1 is foreign key
CaseI->select table2.pkey2,table1.col1 ,table2.col12
from table1 inner join table2
on table1.pkey1=table2.pkey1
where (table1.col3>100 and table1.col3<300 ) and table2.pkey1=2020 and table2.col13 is not null
CaseII->select table2.pkey2,table1.col1 ,table2.col12
from table1 inner join table2
on table1.pkey1=table2.pkey1
where (table1.col3 between 101 and 299 ) and pkey1=2020 and table2.col13 is not null
Cheers :)
vinod
__________________
Cheers :)
vinod
|
