Oracle 参数 GLOBAL_TXN_PROCESSES 官方解释,作用,如何配置最优化建议
本站中文解释
GLOBAL_TXN_PROCESSES参数是Oracle数据库11g中支持分布式事务处理的参数,用于指定Oracle数据库支持全局事务处理的最大进程数,默认值为4,可以设置在1至255之间,数字越大,支持的分布式事务处理数量就越多,但也会增加OVM的开销,因此,根据实际情况量力而为。
要正确设置GLOBAL_TXN_PROCESSES参数,首先要确定当前启动的系统的依赖和运行任务的数量。考虑到性能的要求,如果系统中包含复杂的事务,而且想要尽可能的提高性能,可以将GLOBAL_TXN_PROCESSES参数的值设置的比较大,一般设置为2倍于最大访问数量,但是不要超过255,最好能定期调整这个参数,以便获得最佳性能。
官方英文解释
GLOBAL_TXN_PROCESSES
specifies the initial number of GTXn background processes (GTX0, … GTX9 and GTXa, … GTXj) per instance to support global (XA) transactions in an Oracle RAC environment.
Property | Description |
---|---|
Parameter type |
Integer |
Default value |
|
Modifiable |
|
Modifiable in a PDB |
No |
Range of values |
|
Basic |
No |
Oracle RAC |
Multiple instances can have different values. |
If you want to disable the GTXn background processes, then you must set GLOBAL_TXN_PROCESSES
to 0
in your parameter file. Setting this parameter to 0
will disable the XA support on an Oracle RAC database. Error ORA-55712
will be returned if you try to run XA transactions on an Oracle RAC database with this parameter set to 0
. You can change the setting to a nonzero value at run time to turn on the support for XA.
GLOBAL_TXN_PROCESSES
is useful for systems that process global (XA) transactions heavily. You do not need to specify a value for this parameter since Oracle Database automatically determines the number of processes and autotunes them, as necessary. GTXn background processes are only seen in an Oracle RAC environment.
See Also:
Oracle Database
Development Guide for more information about this parameter