Oracle DB Servers

Note: For you to create a new Oracle database monitor, you should have Admin privileges. Minimum User Privileges refers to the user with CONNECT and SELECT_CATALOG_ROLE roles.

Name

 Name of the Oracle server monitor.

Oracle Version

 Refers to the Version of the Oracle Database.

Oracle Start Time

 Refers to the time, when Oracle server was started.

Availability

 Refers to the status of the database server - Available or Not available.

Connection Time

 Refers to the time taken to connect to the database.

Number of Users

This refers to the number of users, executing an SQL Statement.

Database Created Time

Creation time of the database.

Open Mode

Indicates the Open mode of the Instance, which can be either Read Write or Read.

Log Mode

If the transactions are written on the Log, the Log mode will be ARCHIVELOG , or else, the Log mode will be NOARCHIVELOG.

Database Size

Size of the database, in Megabytes.

Average Executions

This is the average number of executions that happens during the execution of every SQL Statement.

Reads

Refers to the number of reads from the database.

Writes

Refers to the number of writes to the database.

Block Size

This refers to the lowest possible storage area for an Instance, in bytes.

Name

Refers to the name of the Table space.

Allocated Bytes

Refers to the size of the Table space, in bytes.

Allocated Blocks

Refers to the number of allocated blocks in Table space.

Data Files

Refers to the number of data files in Table space.

Name

Refers to the name of the Table space.

Status

Tablespace status: ONLINE, OFFLINE, or INVALID (tablespace has been dropped)

Free Bytes

Refers to the available free space, in bytes.

Free Blocks

Refers to the number of free blocks in Table space.

Reads

Refers to the number of reads from the Table space.

Writes

Refers to the number of writes on the Table space.

Read Time

Time taken for a single read from the Table space.

Write Time

Time taken for a single write on the Table space.

Buffer Cache Size

The total size of the Buffer Cache, given in bytes.

Shared Pool Size

The size of the shared pool given, in bytes.

Redolog Buffer Size

The size of the buffers for the Redo Logs, in bytes.

Library Cache Size

The size of the Library Cache given in bytes.

Data Dictionary Cache Size

The cache size of the data dictionary or row cache in bytes.

SQL Area Size

The size of the SQL Area for usage of SQL/PL statements (bytes).

Fixed Area Size

The size of the SGA, which is fixed throughout the instance.

Buffer Hit Ratio

When a scan of the buffer cache shows that there are no free buffers, Database Block Writer determines which blocks are to be eliminated, based on a least recently used algorithm or LRU. Having a block, required by a user process in the buffer cache already, is called a buffer cache hit or is determined as a ratio. Hits are good, because they reduce the amount of disk I/O, required for the user process.

Data Dictionary Hit Ratio

The purpose of the row or dictionary cache is to store rows of information from the data dictionary in memory, for faster access. The row cache is designed to hold the actual rows of data from objects in data dictionary. While this data is held in the row cache, the users of the database may access that information more quickly, than if Oracle had to read the data into memory from disk. The ratio of the data gets to the data misses in the row cache is Data Dictionary Hit Ratio.

Library Hit Ratio

The Library cache stores all shared SQL and PL/SQL blocks, along with their parse trees. In OLTP environments, where a large numbers of users are entering and exchanging data, there is a great chance of overlapping the parse and execute needs of those different queries. Such an overlap in the library is called a cache hit and the ratio determined to the misses and hits is called Library Cache Hit Ratio.

Free Memory

Refers to the size of the free memory, in bytes.

Data File Name

Name and location of the data file.

Table Space Name

Name of the Table space.

Status

If a data file is a part of the system table space, its status is SYSTEM (unless it requires recovery). If a data file in a non-SYSTEM table space is online, its status is ONLINE. If a data file in non-SYSTEM table space is offline, its status can be either OFFLINE OR RECOVER.

Created Bytes

Size of the Data file, in bytes.

Reads

Refers to the number of reads from the Data file.

Writes

Refers to the number of writes to the Data file.

Average Read Time

Refers to the average read time.

Average Write Time

Refers to the average write time.

ID

Session Identifier for the connected session.

Status

Current status: ONLINE, OFFLINE, or INVALID (tablespace has been dropped).

Machine

Name of the operating system user.

User Name

Name of the Oracle process user.

Elapsed Time

Time elapsed in seconds after which the user has logged into the oracle server.

CPU Used

CPU centiseconds (divide by 100 to get real CPU seconds) used by this session.

Memory Sorts

Number of memory sorts performed.

Table Scans

Number of table scans performed.

Physical Reads

Physical reads for the session.

Logical Reads

Sum of consistent gets and db block gets.

Commits

Number of commits made by user in a second.

Cursor

Number of cursor currently in use.

Buffer Cache Hit Ratio

Percentage of session logical reads taking place from the buffer (1-physical reads/session logical reads*100).

Segment Name

Name of the rollback segment.

Table Space Name

Name of the tablespace, containing the rollback segment.

Status

ONLINE, if the segment is online, or PENDING OFFLINE, if the segment is going offline, but some active (distributed) transactions are using the rollback segment. When the transaction(s) complete, the segment goes OFFLINE.

Current Size

Current size, in bytes, of the rollback segment.

Initial Extent

Initial extent size, in bytes.

Next Extent

Secondary extent size, in bytes.

Min. Extent

Minimum number of extents.

Max. Extent

Maximum number of extents.

Hit Ratio

Ratio of gets to waits. This should be >= 99%.

HWMSize

High Water Mark of rollback segment size.

Shrinks

Number of times rollback segment shrank, eliminating one or more additional extents, each time.

Wraps

Number of times rollback segment wraps from one extent to another.

Extend

Number of times rollback segment was extended, to have a new extent.

ID

Session Identifier for the connected session.

User Name

Name of the Oracle process user.

Event

Resource or event, for which the session is waiting

State

Wait state:
0 - WAITING (the session is currently waiting)
-2 - WAITED UNKNOWN TIME (duration of last wait is unknown)
-1 - WAITED SHORT TIME (last wait <1/100th of a second)
>0 - WAITED KNOWN TIME (WAIT_TIME = duration of last wait)

Wait Time

A non-zero value is the session's last wait time. A zero value means, the session is currently waiting.

Seconds in Wait

If WAIT_TIME = 0, then SECONDS_IN_WAIT is the seconds, spent in the current wait condition. If WAIT_TIME 0, then SECONDS_IN_WAIT is the seconds, since the start of the last wait, and SECONDS_IN_WAIT - WAIT_TIME / 100 is the active seconds, since the last wait ended.

Buffer Gets

Number of buffer gets for the child cursor.

Executions

Number of executions that took place on the object. since it was brought into the library cache.

Buffer Gets per Executions

The ratio of buffer gets to execution in the current polling interval.

Query

First thousand characters of the SQL text for the current cursor.

Disk Reads

Number of disk reads for this child curso.r

Executions

Number of executions, that took place on this object, since it was brought into the library cache.

Disk Reads per Executions

The ratio of disk reads to execution in the current polling interval.

Query

First thousand characters of the SQL text for the current cursor.

Id

Session identifier of Session, holding a lock.

Serial 

Session serial number. Used to uniquely identify a session's objects. Guarantees that session-level commands are applied to the correct session objects, if the session ends and another session begins with the same session ID.

Machine

Operating system machine name.

PROGRAM

Operating system program name.

Waiting Session ID

ID of Session waiting for lock.

Holding Session ID

ID of Session holding lock.

Lock Type

The lock type.

Mode Held 

The mode held.

Object Name

Name of the locked object.

Session Id 

Session Id of locked object.

Serial   

Session serial number. Used to uniquely identify a session's objects.

Lock Mode

Mode of lock.