This function is used to visualize the main properties of the data base when the database under utilization is Oracle™.

The data displayed here cannot be modified.
The modification must be done via the admin tools specific to the database used.

Warning

This function is used, by the requests in the tables and the system views, to give technical information on the database. The interpretation of the results given by this function is up to the database administrator and can depend on the version of the database used.

Screen management

This function is used to visualize the database properties.
These elements are displayed in three tabs: the first one gives the general characteristics, the second one gives the list of parameters and options set at the starting time of the database and the third one gives information on the memory used by the database.

Header

Used to identify the characteristics of the database used.

Database (field BDDNAM)

Name of the database.
Version (field VER)

Version number of the database.
field VERDES

Description of the database version.

Tab General

The first tab displays the general properties of the database.

This screen is made up of two sections:

Information on the database

This first block contains the main characteristics of the database.

NLS parameters

This block is used to visualize the information on usual character strings for the database, the instance and the current session.

Block number 1

Machine (field SRVMAC)

Name of the server on which the database is started.
Instance (field SRVINS)

Name of the instance used to identify in a unique manner for a specific instance when several instances share the name of common services

Date created (field CREDAT)

Date and time of the database creation
field CREHOU
Start date (field STRDAT)

Date and time of the database start-up
field STRHOU
ARCHIVELOG mode (field LOGMOD)

Indicates if the ARCHIVELOG mode is activated or de-activated.

  • NOARCHIVELOG :
    In mode, NOARCHIVELOG, the redo log online files are re-written each time a redo log online file is completed and where a log switch is launched. LGWR does not re-write a group of redo log files whilst the checkpoint for this group is not completed.
  • ARCHIVELOG :
    If the database is configured in the mode ARCHIVELOG mode, the the completed redo groups must be archived. As all modifications carried out on the database are recorded in the redo log online files, the DBA can use the backup present on the hard disk and the archived redo log files to restore the database without losing any committed data.

    It is possible to archive the redo log files :
    - Manually.
    - Automatically : Recommended method.

    The initialisation parameter LOG_ARCHIVE_START, when it is TRUE indicates that the archiving is carried out automatically. When set to FALSE, indicates that the DBA is carried out manually. In automatic mode, the archiving is carried out thanks to the ARCn process and manually with SQL requests.

 

Number of users (field NBRUSR)

Number of users defined in the database.
Number of active connections (field NBRPRO)

Number of active connections on the database.

Grid NLS parameters

Parameter (field PAR)

Display the parameters on the current character sets and their values for the database, the instance and the session.

The parameters present depend on the Oracle version. These parameters cannot be modified from this option.
Database (field BDDVAL)
Instance (field INSVAL)
Session (field SESVAL)

Tab Parameter Definitions

The second tab displays the list of initialization parameters and their values. The type of value -default or specific- is also indicated.

Grid

Parameter (field PAR)

Display the initialization parameters for the database and indicate if it is the default value.

The parameters present depend on the Oracle version. These parameters cannot be modified from this option.
Value (field PARVAL)
Default value (field DEFVAL)
Description (field DES)

Tab Memory

The third tab displays the information about the use of database memory.

This screen gives information on the two memory zones of an Oracle database.

SGA (System Global Area) memory

This is the memory field that contains the data structures that can be accessed for all the processes. It manages data sharing between different users.

This memory field is composed of different elements:

  • Shared pool: this parameter gives the size of the shared pool. The shared pool contains -among others- shared cursors, stored procedures, control structures and message buffers of the parallel execution. High values enhance the performances in the multi-user systems. Low values use less memory. This value is assigned to the initialization file parameter SHARED_POOL_SIZE. Note: 'Shared pool' is a dynamic parameter.
  • Buffer cache: specifies the number of buffers contained in the database buffer cache. The size of the buffer located in the cache corresponds to the size of an Oracle data block (specified by the initialization DB_BLOCK_SIZE); as a consequence, each database buffer located in the cache can contain one single block of data which is read from the data file. The size of the cache is limited therefore all disk data cannot be contained in the cache. This value is assigned to the initialization file parameter DB_CACHE_SIZE(10g) or DB_BLOCK_BUFFERS.
  • LARGE POOL memory field: used to specify the memory proportion assigned to the LARGE POOL memory zone. This memory proportion is used by the shared server as a session memory, by the parallel process for message buffers and by the E/S buffer save on the disk. This value is assigned to the initialization file parameter LARGE_POOL_SIZE.
  • Java pool: specifies the Java pool size. This value is assigned to the initialization file parameter JAVA_POOL_SIZE.

A graph displays the memory assignment that each SGA component uses.

PGA (Program Global Area) memory

This is the memory field that contains all the data that do not need to be shared. It manages the functioning of various processes.


This figure shows the use of each of the memory zones:

../FCT/ORAPROP_001.gif

SGA memory

field TXTAUT

Automatic management of the shared memory (10g)

This value is assigned to the initialization file parameter SGA_TARGET.

If SGA_TARGET is indicated, then the following memory fields are automatically sized :

  • Buffer cache (DB_CACHE_SIZE)

  • Shared pool (SHARED_POOL_SIZE)

  • Large pool (LARGE_POOL_SIZE)

  • Java pool (JAVA_POOL_SIZE)

  • Streams pool (STREAMS_POOL_SIZE)
field FILL01
field FLGAUT
field TXTTOT

Total size of the SGA memory.

The fixed size of the SGA corresponds to the memory allocated for the SGA field that contains the general information on the status of the database and on the instance.

Total size of SGA = shared pool + buffer cache + memory field LARGE POOL + java pool+ log buffer
field FILL02
field VALTOT
field UNITOT
field TXTMAX

Maximum size expected by the SGA memory from the start-up of the database.

field FILL03
field VALMAX
field UNIMAX

Table number 2

Description (field INFPAR)

Graph displaying each SGA component and the memory size that it uses..

SGA memory (field INFVAL)

Table number 1

field PARAM

Grid displaying each SGA component and the memory size that it uses..

field VALEUR
field UNITE

PGA memory

field TXTPGACUM

Total for the PGA targets : target number for all the PGA memories.

field FILL04
field VALPGACUM
field UNIPGACUM
field TXTPGA

Quantity of PGA memory actually allocated : PGA memory actually in use.

field FILL05
field VALPGA
field UNIPGA
field TXTPGAMAX

Maximum quantity of the allocated PGA memory (from the start-up) : Maximum allocated PGA memory.

field FILL06
field VALPGAMAX
field UNIPGAMAX
field TXTPGARAT

Success percentage in cache memory : frequency on which the data is found in the memory cache, avoiding disk access.

field FILL07
field PGARAT

Specific Buttons

Refresh

This button, also accessible using the short cut, used to refresh the display of the tabs.

Error messages

The only error messages are the generic ones.

Tables used

SEEREFERTTO Refer to documentation Implementation