Db2
As long as your usage of all binary (COMP) data items in the application conforms to the PICTURE and USAGE specifications and your binary data was created by COBOL programs, you can use TRUNC(OPT) to improve performance under Db2®.
This is recommended in performance sensitive Db2 applications. If your usage of any binary data item does not conform to the PICTURE and USAGE specifications, you should use COMP-5 data types or use the TRUNC(BIN) compiler option. If you were using NOTRUNC with your OS/VS COBOL programs without problems, TRUNC(OPT) on COBOL for MVS™ & VM, COBOL for OS/390® & VM, and Enterprise COBOL behaves in a similar way. For additional information on the TRUNC option, please refer to TRUNC.
The RENT compiler option must be used for COBOL programs used as Db2 stored procedures.
For the best performance, make sure that you use codepages that are compatible to avoid unnecessary conversions. For example, if your Db2 database uses codepage 037, but you use the CODEPAGE(1140), SQL, SQLCCSID compiler options, the performance can be slower than using either CODEPAGE(037), SQL, SQLCCSID or CODEPAGE(1140), SQL, NOSQLCCSID since the first set of options require conversions to match the codepage but the second and third set of options do not require such conversions.