Oracle Database - Session

Card Puncher Data Processing

About

One session = One connection = One transaction (one user behind its screen)

For session variable, see Oracle Database - (Application) Context

Session Id

  • SESSIONID - The auditing session identifier. You cannot use this attribute in distributed SQL statements.
  • SID - The session ID.

You can get the current values for a session with the help of the userenv context.

Vsession

When the username is null, this is server activity not client activity. The program runs oracle.exe.





Discover More
Data System Architecture
Concurrency - Latches (System Lock)

Latches are like semaphores. Latches are used to guarantee physical consistency of data, while locks are used to assure logical consistency of data. Latches are simple, low-level system lock (serialization...
Card Puncher Data Processing
Oracle Database - (Application) Context

An application context is a set of (name-value|variable-value) pairs that Oracle Database stores in memory during a session. Oracle provides a built-in namespace called USERENV, which describes the current...
Card Puncher Data Processing
Oracle Database - CURRENT_SCHEMA

When a session starts, CURRENT_SCHEMA has the value of the schema owned by SESSION_USER. To get the current value of CURRENT_SCHEMA, CURRENT_USER, or SESSION_USER, use the userenv context: CURRENT_SCHEMA...
Toad Lock
Oracle Database - Locks

Lock Mechanism in Oracle Oracle Database provides: data concurrency, consistency. The data a session is viewing or changing must not be changed by other sessions until the user is finished. and...
Card Puncher Data Processing
Oracle Database - Memory

Oracle have two Memory spaces: SGA memory which is shared by all sessions connected to Oracle Database. See and PGA memory which is allocated for each session. See With SQLPlus
Oracle Database Sga
Oracle Database - System Global Area - SGA (Shared Memory)

The SGA (System Global Area) is an area of memory allocated when an Oracle Instance starts up. The SGA memory is shared by all sessions connected to Oracle Instance. See A group of shared memory structures...
Card Puncher Data Processing
Oracle Database - TIMED_STATISTICS parameter

The V, V, V, and V views provide information on what resources were waited for, and, if the configuration parameter TIMED_STATISTICS is set to true, how long each resource was waited for.
Card Puncher Data Processing
Oracle Database - Userenv (Current Session Informations)

Userenv is a pre-build context that describes the current session. You can query the context Userenv with two functions. the SYS_CONTEXT...
Oracle Database Direct Path Read Temp With Parallel Slave
Oracle Database - direct path read temp and direct path read wait event

“direct path read temp” and “direct path read” event are wait events. When a session is reading buffers from disk directly into the PGA (opposed to the buffer cache in SGA), it waits on this event....



Share this page:
Follow us:
Task Runner