Can somebody please help me out how to migrate data from Ingres to Oracle10g?
some of the other clarifications are
1. There is copydb option in ingres/visual dba and it asks directory name, source directory, destination directory. what it means?
2. How to describe structure of a table in ingres?
3. How to check the version of present ingres database?
4. is there any document for reference, if there please share it with me or give hyperlink.
Reading what you've said, I have an impression that you don't know Ingres at all, do you? If that's correct, I'm afraid that you'll spend many sleepless nights in the future. Here's how I see it:
you don't know Ingres, but you do know Oracle: find someone who knows Ingres and - above all - designed that "database" (i.e. knows tables' descriptions, relations between these tables, data stored within, etc.). That person could prepare Ingres data for you - for example, CSV files - and you'd then "import" them into your Oracle database (using SQL*Loader, external files, whatever). Without knowing WHAT is stored in Ingres, I have no idea how would it be possible for you to create a data model in an Oracle database that would successfully accept Ingres data in a meaningful manner.
you don't know Ingres, and you don't know Oracle: impossible mission, find something else to do
you know Ingres, but you don't know Oracle: I don't think so, at least the first part.
you know Ingres and you know Oracle: not very likely, otherwise you wouldn't be here asking questions you ask
So, it seems that there are not that many options there.