This post will go though the steps needed to upgrade an Oracle Grid High Availability Services (HAS) from version 12c (12.1.0.2) to 19c (19.13.0) on a Linux environment. 1:- As per document Doc ID 2539751.1, Patch 28553832 is a prerequisite for both GI and DB Upgrade. Here the steps to apply Oct 2021 PSU which... » read more
This activity is part of a GI upgrade from 12.1.0.2 to 19c, in which we need to apply latest PSU first, so here are the steps: 1:- Patches available here: 2:- (as ROOT) Update OPACH version to latest available. (p6880880_122010_Linux-x86-64.zip) 3:- (as ROOT) Run prepatch script. (RDBMS instances should be stopped first) 4:- GI patching:... » read more
Setting up Network Encryption in our Oracle environment is very easy, we just need to add these lines to the sqlnet.ora on server side: Ideally, on the client side we should add these too: But since ENCRYPTION_CLIENT by default is ACCEPTED, if we see this chart, connection would be encrypted (ACCEPTED – REQUESTED case) Lets... » read more
We had this error while trying to open a DB: Digging a bit on the enviroment, we noticed server had a power cut and DB did not stop gracefully. This is how we fixed: 1:- Start DB in mount and list log files: 2:- Recover Database: (we need to input the failed log file): 3:-... » read more
The reason to trace the CBO is to understand why the Optimizer made some decisions. In this example we are going to see why same query sometimes uses an index and others it doesn’t, same example was explained HERE It is always useful to have a “GOOD” and “BAD” execution, this way it is easier... » read more
You might face this question if you are going though job interviews. and these are some cases where the Optimizer thinks going for a full table scan is better than index scan. 1:- The selectivity of the records is very high: We have this table and range of contents: We have an index and it... » read more
On this activity we are going to generate snapshots on an active standby so we can be able to create AWR reports. This is our setup: We need to perform the following steps to enable AWR reporting from a physical standby database. 1:- Unlock SYS$UMF user and reset the password. SYS$UMF account is used to... » read more
On this activity we are going to create a Physical Standby from a 19c in CDB configuration: These are the details for the primary DB: Our plan is to create a Standby DB with these details: STEPS: 1:- Prepare Primary database Enable force logging and archivelog mode: Create Standby Redo Log (SRL) files: **We are... » read more
On this practice, we are going to configure DATAGUARD BROKER in a new PRIMARY/STANDBY configuration and see what errors we get since this is a new setup. This is our current lab: 1:- Add the DG broker files to ASM on both primary and Standby: 2:- Start DG broker at DB level on both systems:... » read more
On this post we are going to review possible errors we can face while creating a Standby DB with RMAN using an active DB. These are just errors I faced. For some I skipped steps on purpose so we can see the error we would face. You might face these, or others ( or none…)... » read more