What do the concepts of Oracle Locks mean? When should we use each one? And the most crucial question: how to avoid each scenario?
A standby database is a DRP (Disaster Recovery Plan) solution, and it is nothing but a copy of the primary database, which can be automatically synchronized with Dataguard. Either using Dataguard or shell scripts for automatic or manual synchronization, the primary database must operate in archive mode.
Once and again, developers ask me the same question: “I want to build the following index, do you think it is right?”
I will assume that the developer analyzed the functional use of the index correctly, so I can explain you how to test the impact of the index in your production environment.
If you are an experienced production database administrator, I am pretty sure that from time to time you have to hear “The problem is the database, it is running slow”.
If you are a junior DBA, trust me when I tell you that you will hear that, more times and more frequently than you would wish to on your daily job.
In general, we write down SQL sentences and we execute them whithout analyzing any metrics. Metrics are important. A small improvement is multiplied by the times the statement is executed
Several times we may need to make a lock/release at a database row level. Let me expose a simple situation so you can then relate it to your particular problem in our web service or software in general.