Running explain plan on a prepared statement

Question

I'm using IBatis to run queries against an Oracle database. IBatis runs the queries as prepared statements. I want to run explain plan on the prepared statements.
I already have a shim -- a proxy java.sql.Connection object -- that takes the SQL used to create a prepared statement (e.g., "select a, b, c from table d where c = ?"), returns a proxy java.sql.PreparedStatement, and then on the PreparedStatement's execute(), interpolates the bound parameters into the SQL statement, and runs Explain Plan on that (e.g, preparedStatement.setInt(5) is called, followed by preparedStatement.execute(), which results in my proxy running "explain plan for select a, b, c from table d where c = 5;")
Using Spring configuration, I can transparently insert the shim and get explain plans for all queries run through that Connection.
The problem is this: I'm explaining the plan for the SQL with the bound parameters, not necessarily the SQL run for the prepared statement.
Assume that in the above example, there exists an index on column c in table d, and that 5% of d's rows have the value 1, 15% have the value 2, and 80% have the value 3.
For "select a, b, c from table d where c = 1", Oracle will use the index. But for "select a, b, c from table d where c = 3", Oracle will do a full table scan.
What I want to know is what Oracle will do for "select a, b, c from table d where c = ?" when "?" is an unknown, arbitrary value subsequently bound to 1 or to 3.
As I understand it, the query plan for a prepared statement is done once, when the prepared statement is created. At execute time (as I understand it), the query plan is not reformulated based on the actual bound values (though partition pruning is recalculated).
So how can I find out what query plan is actually be used for prepred statement?
Thanks.

Answer 1

I already have a shim -- a proxy java.sql.Connection object -- that takes the SQL used to create a prepared statement I believe explain plan is part of PL/SQL rather than external to it.
As such you can pass it via a prepared statement. It is just a matter of getting the syntax correct. And of course collecting the result.
The syntax is going to be be something like the following. You would use it just like you use the existing sql.
begin
   select ... from ... where c = ?;
endThe result might be returned a result sets (plural). If so you would need to code appropriately for that.