Under the old compiler, the MACRO preprocessor would uppercase all text except for text enclosed in strings and comments. But the old compiler recognized only text delimited by '...' as strings: text delimited by "..." was not recognized as a string and was uppercased.
The new compiler will, under the default preprocessor option of CASE(UPPER) also uppercase all text except for text enclosed in strings and comments. However, the new compiler recognizes both text delimited by '...' and text delimited by "..." as strings and will not uppercase either.
This difference could cause a problem if you were running the MACRO preprocessor before the SQL preprocessor and if you also had code in your SQL statements such as:
WHERE "system" = 'Wilmer'
Under the old compiler, this would have become:
WHERE "SYSTEM" = 'Wilmer'
But under the old compiler, this becomes:
WHERE "system" = 'Wilmer'
The latter would probably not produce the results you want from DB2. If this is the case, you must change your source so that the text delimited by "..." is in uppercase (before any preprocessing).