Re: Indexed PF vs. LF performance

Whenever I can I key my physical files and make them unique.

I have some table files that I
RGZPFM FILE(MYFILE) KEYFILE(*FILE)
whenever I add records. Doing it on most files make sense. UNLESS you
primarily access by a different order. An example might be a name file.
If a vast majority of accesses are by name and rarely by the 'key' it
might make sense to reorg that by logical built over the name. Even this
could be improved upon. Most PF's that are keyed omit the active record
code from the key. Those it might be better to reorg by a key that is
built over active record id and then the key.

Our ERP software never keys the PF. They never specify unique in their
LF's either. They try to get uniqueness by imbedding the logic into
programs. When we do merges, acquisitions, migrations, etc., we often
have to scrub the data to get uniqueness. Imagine an item number in the
file twice. Once with an active record flag, again with an inactive
record flag.

I prefer to protect database integrity by using primary unique keys, by
using foreign keys, by using check constraints, by journalling, etc. Stuff
that most of DDS rarely even pays lip service to.

Rob Berendt