Outer join
can be created using this addition to the where clause in a select
statement. It speeds up the performance tremendously, but the cons
of using this variation are listed below
-
Duplicates are automatically removed
from the resulting data set. Hence care should be taken that the
unique key of the detail line items should be given in the
select statement.
-
If the table on which the For All
Entries IN clause is based is empty, all rows are selected into
the destination table. Hence it is advisable to check
before-hand that the first table is not empty.
-
If the table on which the For All
Entries IN clause is based is very large, the performance will
go down instead of improving. Hence attempt should be made to
keep the table size to a moderate level.
Not
Recommended
Loop at int_cntry.
Select single * from zfligh into int_fligh
where cntry = int_cntry-cntry.
Append int_fligh.
Endloop.
Recommended
Select * from zfligh appending table int_fligh
For all entries in int_cntry
Where cntry = int_cntry-cntry.
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