Re: Is there a way to dump all the plans considered by optimizer into log?

[Bryan Pendleton]

I didn't find any easy way to enable it (like setting a property). So
what I ended up with, was to define two stored procedures:

     public static void trace() {
         org.apache.derby.iapi.db.OptimizerTrace.setOptimizerTrace(true);
     }

     public static void printTrace() {
         
System.out.println(org.apache.derby.iapi.db.OptimizerTrace.getOptimizerTraceOutput());
     }

     s.execute("create procedure trace() language java parameter style java external name 
'" + getClass().getName() + ".trace'");
     s.execute("create procedure print_trace() language java parameter style java external 
name '" + getClass().getName() + ".printTrace'");

And then call trace() before the statement to trace, and printTrace()
after:

     s.execute("call trace()");
     s.execute("select 1 from sys.sysschemas natural join sys.systables");
     s.execute("call print_trace()");

Might we consider permanently including these, and putting them in, say,
the SYSCS_DIAG schema, so it would be something like:

        s.execute("call SYSCS_DIAG.OPTIMIZER_TRACE(1)");
        ...
        s.execute("call SYSCS_DIAG.OPTIMIZER_PRINT_TRACE()");
        s.execute("call SYSCS_DIAG.OPTIMIZER_TRACE(0)");

thanks,

bryan