ABAP_to_the_Future

15
ABAP Programming for SAP HANA
This is, unfortunately, part ly a manual task. When you have to resort to using
database-specific features, it’s due to a specific problem only your organization’s
SAP system is having, and thus it’s difficult for SAP to provide an automated tool
to look for such occurrences. (Having said that, there are some automated checks
that can be performed using the Code In spector; these are covered in Section
15.5.3.)
One example of database-specific code in a custom program (it can also be found
in SAP standard programs) is “database hints,” which you can add to your ABAP
SELECT statements, as in Listing 15.21.
SELECT SINGLE monster_number
FROM zt_monsters
INTO ld_monster_number
WHERE monster_name EQ ld_monster_nmae
%_HINTS ORACLE 'index(ZT_MONSTERS "ZT_MONSTERS~Z01")'.
Listing 15.21 SELECT with a Database Hint
Normally, the database optimizer chooses what index to use, but if that optimizer
keeps choosing the wrong index, then you can force the issue using a HINT (i.e.,
make the optimizer use the index you think is best).
The recommendation from SAP has always been never to use database hints, on
the grounds that one day you might want to do a database migration. In this situation,
the cows have certainly come home to roost; this is precisely what you’re
doing—moving to SAP HANA—so you need to get rid of all these HINTS statements.
The other database-specific type of coding you might come across in custom code
is NativeSQL. This is when the specificdatabase you are using has SQL commands
not available in OpenSQL, and you want to take advantage of this, so you write
some Oracle- or Microsoft-specific SQL inside the ABAP constructs EXEC SQL /
ENDEXEC.
Naturally, SAP recommends against this as well, and there are two good reasons
that you should replace such NativeSQL with OpenSQL:
왘 Such a query will no longer work once you’ve migrated to SAP HANA.
왘 With all the advances that ABAP 7.4 brin gs to OpenSQL, it’s more than likely
that the missing functionality that ca used the original programmer to use
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