Oracle Patches Patches are used to correct the bugs. It will change the last number of the version. 11.2.0.3.0 to 11.2.0.3.1 – PSU Ex: 10g -10.2.0.4.0 version – alter system flush shared_pool/buffer_cache will not work 11g -11.2.0.3.0 version – $nid DB newid will not work. (Changing DB ID) Types of Patch: Opatch – Oracle patch (It will fix only one bug) CPU – Critical patch update (Every quarter once) PSU – Patch set update (Bundle patch) 2.0.3.0 to 11.2.0.3.1 Opatch CPU PSU One off patch Security patch Bundle patch Size will be in KB Size will be min 80 MB to Max 150 MB Size will be min…