I have a database on which users can execute queries. To ensure they cant view each others information I want to execute this query first: dbms_session.set_context(‘usernameParam’, ‘username’, username); I then want to create views that look like this: CREATE OR REPLACE VIEW “MyView” AS SELECT * FROM “DB”.”MyTable” WHERE “Username” = SYS_CONTEXT(‘usernameParam’, ‘username’) / I then want my clients to use the views instead of tables.

I am doing this using Java. I get a database connection. Using that connection I execute the set_context query. I am wandering, how thread safe is this? If 2 clients at the same time execute a query is it possible that the set_context will be execute in the wrong order and clients see each others information or does the set_context apply only to the current connection even thought the same username is used to connect to the database?

We’re on the same page. I discovered this handy thing around the same time:

http://thinkoracle.blogspot.com/2005/07/which-instance-am-i-in.html

Very handy!

USERENV is a legacy function that is retained for backward compatibility. Oracle Corporation recommends that you use the SYS_CONTEXT function with the built-in USERENV namespace for current functionality