Is there any quickest way or command to find out

1.Identity column in a table

2.Primary key column and keys

3.Ref. Integrity/foreign Key

TIA.

Run the db2look against the table and it will give you everything you need, look at the options to get what you need in the output

Instead of running the DB2LOOK utility you can just run queries against the catalog views to gather the information you want.

I´d suggest you pay a visit to the SQL References to for a description about those views (SYSCAT schema).

For a start, according to the information you requested, take a look at the: SYSCAT.TABLES, SYSCAT.COLUMNS, SYSCAT.INDEXES, SYSCAT.REFERENCES, SYSCAT.TABCONST.

Depending on what you´re trying to do, it´ll have a better result than the DB2LOOK utility.

Now, if you just want to get the DDL statements to backup the structure, or copy it to another location, I strongly recommend using the DB2LOOK.

Hope it helps.
Fernando