ORA-04031: unable to allocate 2097152 bytes of shared memory ("shared pool","unknown object","hash-join subh","QERHJ Hash Table

We getting the following error in our database: ORA-04031: unable to allocate 2097152 bytes of shared memory ("shared pool","unknown object","hash-join subh","QERHJ Hash Table Entries")" We have already tried the following: 1. Flushing shared pool 2. Bouncing db Bouncing does resolve the problem temporarily but then it comes back