[SAP HANA] HANA 参数管理

1. 参数管理
2. tenant 的参数管理
3. 参数的物理位置
4. 参数的作用域

1.参数管理

　　SAP HANA 2.0 SPS04 view CONFIGURATION_PARAMETER_PROPERTIES and M_CONFIGURATION_PARAMETER_VALUES，检查哪些参数需要重启系统，在那个ini 文件存储，描述，作用，默认值，单位（ms,md,Day 等等），推荐值，使用限制（rangle,layer,custom,system_managed），只读。

　　SAP HANA 2.0 SPS04 需要重启和无效的参数会出现alert

M_CUSTOMIZABLE_FUNCTIONALITIES display metadata and properties of the public configuration parameters for SAP HANA.
M_CONFIGURATION_PARAMETER_VALUES display landscape service parameter values，可以识别修改参数是否需要重启系统。

CONFIGURATION_PARAMETER_PROPERTIES 显示metadata 和SAP HANA  公共配置属性

  2. tenant 参数，

• • backlist parameter for tenant usage　　　　multidb.ini need INIFLE ADMIN
  • disable features for a tenant 　　　    　   　system view　M_CUSTOMIZABLE_FUNCTIONALITIES provides information about those features that can be disabled and their status，this view exist in the SYS schema .SYS_DATABASES 在system数据库，显示所有数据库激活的特性在
  • additional SAP HANA feature　　               SYS_DATABASES enablement of feature in all Database.

Note:

system properties that are included in the multidb.ini by default cannot be changed by the tenant db admin.
but system admin can still change these properties in the system db in all layers.the multidb.ini file shows the blacklisted parameter for the tenant db as read-only

select "name","description","is_enabled" from "SYS"."M_CUSTOMIZABLE_FUNCTIONALITIES"

 3.参数文件位置 :

• Default  configurations:　　 　　    /usr/sap/<SID>/HDB<instanc>/exe/config (read only)
• system configurations:                 /usr/sap/<SID>/SYS/global/hdb/custom/config
• Tenant-specific configurations:      /usr/sap/<SID>/SYS/global/hdb/custom/config/DB_<tenant-name>
• Host-specific configurations:         /usr/sap/<SID>/HDB<instance number>/<hostname

4. 参数的作用域

• default :系统的默认值
• system 列,当前系统配置的值,如为空,使用默认值
• DB列,对基本个DB起作用
• host 列,只对某个host

Layer	Description
System	The value configured for the system applies to the system as whole, including all hosts of multi-host systems and all tenant databases of multi-DB systems.
Host	For some properties, it is possible to set host-specific values if the system has multiple hosts. If host-specific values are possible, you can expand the Hosts area of the Change Configuration Value dialog box, select the relevant host(s), and enter the host-specific value(s). It is possible to enter both a value for the system as a whole and for individual hosts. In this case, the system-specific value only applies to those hosts that do not have a host-specific value.
Database	For some properties, it is possible to set database-specific values if the system has tenant databases. If database-specific values are possible for a given property, they can be configured both in the system database and the tenant database. From the system database, you can configure database-specific values for all tenant databases in the system. From a tenant database, you can configure database-specific values only for that database. It is possible to enter a value for the system as a whole and individual databases. In this case, the system-specific value only applies to those databases that do not have a database-specific value.

Note: 2036111 - Configuration parameters for the SAP HANA system

　　2600030 Parameter Recommendations in SAP HANA Environments