Negative testing DB2 + NATURAL app exception handling - need advice 1

[novena]

Hi all,

I need to system test an online mainframe interface (written in NATURAL) to a DB2 database. The interface is being written by a developer who's an expert with NATURAL, but a DB2 novice.

I want to make sure that appropriate edits and exception handling routines are in place. Aside from the obvious technique of trying to pass an invalid data type, can anyone suggest any strings, characters or other techniques to try to make the DB2 database choke up or otherwise misbehave?

Thanks,

Jeremy

 

[BrianTyler]

There is not very much that can be done, as the software protects you from most errors.
There are the obvious 'standard' things to test when populating database rows - particularly for dates and timestamps.
One area which could be confusing is the treatment of NULL values - for example the concatenation of several columns, one of which contains null always returns null.
Comparisons between dates and timestamps are to be thought through, depending on the circumstances.
VARCHAR fields often give unexpected results for SUBSTR etc
Indexes are only used if the comparison field is left alone (e.g. UPPER(CITY) will stop it using an index on CITY)

Thats my list, I expect others may add more.

 

[Truusvlugindewind]

Just curious: does the natural source contain the 'native' DML (read/find/histogram) or DB2/SQL?

 

[novena]

Unfortunately, I don't know that. This is 'gray-box' testing on my part, and I don't have access to that part of the source code.

- J