oracle 10g 中cjq0後臺程式的作用
Job Queue Processes
Job queue processes are used for batch processing. They run user jobs. They can be viewed as a scheduler service that can be used to schedule jobs as PL/SQL statements or procedures on an Oracle instance. Given a start date and an interval, the job queue processes try to run the job at the next occurrence of the interval.
Job queue processes are managed dynamically. This allows job queue clients to use more job queue processes when required. The resources used by the new processes are released when they are idle.
Dynamic job queue processes can run a large number of jobs concurrently at a given interval. The job queue processes run user jobs as they are assigned by the CJQ process. Here's what happens:
-
The coordinator process, named CJQ0, periodically selects jobs that need to be run from the system
JOB$
table. New jobs selected are ordered by time. -
The CJQ0 process dynamically spawns job queue slave processes (J000…J999) to run the jobs.
-
The job queue process runs one of the jobs that was selected by the CJQ process for execution. The processes run one job at a time.
-
After the process finishes execution of a single job, it polls for more jobs. If no jobs are scheduled for execution, then it enters a sleep state, from which it wakes up at periodic intervals and polls for more jobs. If the process does not find any new jobs, then it aborts after a preset interval.
The initialization parameter JOB_QUEUE_PROCESSES
represents the maximum number of job queue processes that can
concurrently run on an instance. However, clients should not assume that
all job queue processes are available for job execution.
Note:
The coordinator process is not started if the initialization parameterJOB_QUEUE_PROCESSES
is set to 0.See Also:
for more information about job queues來自 “ ITPUB部落格 ” ,連結:http://blog.itpub.net/161195/viewspace-1052143/,如需轉載,請註明出處,否則將追究法律責任。
相關文章
- oracle 10g 中後臺程式(MMON,MMNL,MMAN,RBAL,OSMB)的作用Oracle 10g
- Oracle 10g 的後臺程式Oracle 10g
- ORACLE 10G 後臺程式Oracle 10g
- Oracle後臺程式及其作用簡介Oracle
- oracle中容易忽略的後臺程式Oracle
- v$bgprocess --解釋oracle db 後臺程式作用的檢視Oracle
- ORACLE後臺程式Oracle
- oracle 後臺程式Oracle
- WINDOWS ORACLE 後臺程式WindowsOracle
- Oracle後臺程式列表Oracle
- Oracle後臺程式的功能簡介Oracle
- oracle 後臺程式的理解筆記Oracle筆記
- Oracle 後臺程式 說明Oracle
- Oracle後臺程式詳述Oracle
- [zt] Oracle RAC 後臺程式Oracle
- Oracle SMON程式的作用Oracle
- ORACLE 11G 新的後臺程式Oracle
- oracle 10g的程式Oracle 10g
- 關於Oracle RAC後臺程式Oracle
- Oracle RAC後臺程式介紹Oracle
- Oracle VKRM 後臺程式介紹Oracle
- oracle架構之後臺程式Oracle架構
- RAC例項中附加的後臺程式
- ORACLE學習幾個重要的後臺程式Oracle
- 在windows下檢視oracle的後臺程式WindowsOracle
- 關於input 中 hidden屬性在後臺作用的例項
- Oracle體系結構之-Oracle後臺程式Oracle
- 實驗,暫停oracle後臺程式Oracle
- ORACLE DG之後臺程式詳解Oracle
- [zt] Oracle10g 後臺程式Oracle
- 【ORACLE】orcle10g後臺程式Oracle
- Expert one on one oracle之後臺程式Oracle
- Oracle程式結構及後臺程式簡介Oracle
- ORACLE 程式的作用及檢視Oracle
- Oracle 10g RAC中的DRMOracle 10g
- 繼續瞭解Oracle部分後臺程式Oracle
- Oracle10g 中AWR相關的兩個新後臺程式MMON及MMNLOracle
- 【eygle】Oracle程式:SMON的功能與作用Oracle