converting from DB2 to Oracle: TIMESTAMP

We are converting an application (written in COBOL) from DB2 to Oracle. On this project I will be working as both the primary support DBA and a member of the programming team. So unlike another project I'm on (see "venting my spleen") I'll be in a very good position to influence application design decisions.

Since Oracle's DATE will only resolve time to seconds, it would appear that the TIMESTAMP fields will have to become either CHAR or NUMBER datatypes (with an application-understood format, and few lines of code coming and going to handle it) I'm looking for best ideas to get the milliseconds, or a resonable facsimilie thereof.

I searched the archives and got the general answer of using a sequence. Even found where I had posted a msg on the same general subject a year ago, but the replies were a bit more vague than what I'm looking for here. One message, on another thread, even said to "use the millisecond portion of the sequence." That's a new one on me.

It would appear that the potential exists for needing to increment the sequence on the order of magnitude of several dozen to a few score times per second.

Any thoughts on best practices for this situation?

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Ed Stevens
(Opinions expressed do not necessarily represent those of my employer.)