SAS Visual Data Builder
provides the
Where and
Having tabs
for filtering data. Follow these best practices:
-
Filter on the
Where tab
first because the WHERE clause reduces the rows to consider for further
subsetting.
-
When you specify a filter on a
column that is an index or primary key, avoid using a function whenever
it is possible. Using a function, such as
CAST(order_id
as DOUBLE), risks a full table scan being performed rather
than using the index.
-
Filter on the table that has the
smallest number of rows first.
-
If you need to remove a table that
is used on the
Where or
Having tabs,
then remove the reference to the table from the filters before you
remove the table from the query. Otherwise, if you remove a table
that is referenced in a filter, all the filtering conditions are cleared.