The QMNC process is to the AQ tables what the CJQ0 process is to the job table. It monitors the… Read more
Category: QMNC and Qnnn
Dedicated Server vs. Shared Server vs. DRCP- Oracle Processes
Before we examine the rest of the processes, let’s discuss why there are three main connection modes and when one… Read more
System Global Area (SGA) Memory Management- Memory Structures
The SGA is a group of shared memory structures that contain data and control structures for an Oracle instance. When… Read more
PMON: The Process Monitor- Oracle Processes
This process is responsible for cleaning up after abnormally terminated connections. For example, if your dedicated server “fails” or is… Read more
Pnnn: Parallel Query Execution Servers-Oracle Processes
Parallel query is the capability to take a SQL statement such as a SELECT, CREATE TABLE, CREATE INDEX, UPDATE, and… Read more
Reduces the Memory Needed on the System- Oracle Processes
This is one of the most highly touted reasons for using a shared server: it reduces the amount of required… Read more
Background Processes- Oracle Processes
The Oracle instance is made up of two things: the SGA and a set of background processes. The background processes… Read more
SMON: The System Monitor- Oracle Processes
SMON is the process that gets to do all of the system-level jobs. Whereas PMON was interested in individual processes,… Read more
RECO: Distributed Database Recovery- Oracle Processes
RECO has a very focused job: it recovers transactions that are left in a prepared state because of a crash… Read more
Automatic Shared Memory Management (ASMM)- Memory Structures
In all of my recent DBA experience (including databases in Oracle’s cloud), this is the most common method for managing… Read more