What is the lifetime of a session?

Question

Hi all,
I am writing a .NET application that queries an Oracle Database. I am altering the Session variable current_schema in order to execute commands with a different default schema than that of the logged in user. The change to current_schema should persist for the duration of the session, but I'm not sure how long this is. Originally I expected it to be the lifetime of the connection, but this is not the case.
The following code illustrates:
public sub getvalue()
Static Dim done As Boolean
Dim daODP As DataAdapter
Dim conODP As New OracleConnection("Data source=oracleInstance;User ID = username; Password = Password")
Dim cmdODP As New OracleCommand("alter session set current_schema = scott", conODP)
daODP = New OracleDataAdapter("Select columnName from TBLNAME", conODP)
If Not done Then
conODP.Open()
cmdODP.ExecuteNonQuery()
conODP.Close()
done = True
End If
conODP.Open()
Dim dsODP As New DataSet
daODP.Fill(dsODP)
conODP.Close()
end sub
The Alter session command is executed only the first time the method is called, however each subsequent call inherits the same 'session' from oracle, because if it didn't then the call would fail. Once the test application is restarted the session is reset.
When is a session created and when is it ended? Is session length a server property? is it dependent on traffic?(eg:timeout) Is it valid for the life of the application?

Answer 1

So, to be clear (I was doing some searching around on connection pooling and sessions just to clarify things in my mind), if I use the default conection pooling enabled then I have to take extra care to ensure that I don't leave anything persistent laying about? For example, package variables set in one transaction could wind up persisting to another transaction by another user if they happen to pick up the connection used by the first user?
Damn, but that really is a pain for anyone with a history of using packages and whose brain just automatically assumes session-persistence for a given user when they're coding - it just simplifies so many things. But I don't particularly care to deal with the overhead of opening and closing connections left and right either. Time-consuming and expensive, especially the way .NET front end users are used to opening and closing them left and right.
Time to do some thinking on this.....