Eddie Awad’s Blog - Latest Comments in SYS_CONTEXT in Oracle

Re: SYS_CONTEXT in Oracle

Pete Johnson — Wed, 23 May 2007 03:14:20 -0000

Hi All

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?

Re: SYS_CONTEXT in Oracle

SIVASANKARAN — Wed, 14 Feb 2007 01:42:46 -0000

Execellent ... It is veryful for me.

Re: SYS_CONTEXT in Oracle

Robert Vollman — Tue, 09 Aug 2005 19:51:55 -0000

Yes!

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

http://thinkoracle.blogspot...

Very handy!

Re: SYS_CONTEXT in Oracle

Eddie Awad — Mon, 08 Aug 2005 18:20:33 -0000

There is a similar function called `USERENV`. But based on the [documentation](http://download-west.oracle...

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