数据库故障中有不少是因为参数设置不合理导致的，因此数据库优化也要从参数优化作为基本要素。
应该只需要将数据库基本初始化参数设置正确有效。下面是数据库基本初始化参数的列表。
•CLUSTER_DATABASE 指定是否启用Oracle RAC的Oracle RAC参数
| Property | Description |
| Parameter type | Boolean |
| Modifiable | No |
| Modifiable in a PDB | No |
| Range of values | true | false |
| Basic | Yes |
| Oracle RAC | For all instances, the value must be set to true. |
•COMPATIBLE 使您能够使用Oracle的新版本，同时确保能够将数据库降级到较早的版本
| Property | Description |
| Parameter type | String |
| Syntax | COMPATIBLE = release_number |
| Default value | 20.1.0.0 |
| Modifiable | No |
| Modifiable in a PDB | No |
| Range of values | 11.2.0 to default release |
| Basic | Yes |
| Oracle RAC | Multiple instances must have the same value. |
•CONTROL_FILES 指定一个或多个控制文件的名称，以逗号分隔
| Property | Description |
| Parameter type | String |
| Syntax | CONTROL_FILES = filename [, filename ] ... |
| Note: The control file name can be an OMF (Oracle Managed Files) name. This occurs when the control file is re-created using the CREATE CONTROLFILE REUSE statement. | |
| Default value | Operating system-dependent |
| Modifiable | No |
| Modifiable in a PDB | No |
| Range of values | 1 to 8 filenames |
•DB_BLOCK_SIZE 指定Oracle数据库块的大小(以字节为单位)
| Property | Description |
| Default value | 8192 |
| Modifiable | No |
| Modifiable in a PDB | No |
| Range of values | 2048 to 32768, but your operating system may have a narrower range |
| Basic | Yes |
| Oracle RAC | You must set this parameter for every instance, and multiple instances must have the same value. |
•DB_CREATE_FILE_DEST 指定oracle管理的数据文件的默认位置
| Property | Description |
| Parameter type | String |
| Syntax | DB_CREATE_FILE_DEST = directory |
| Default value | There is no default value. |
| Modifiable | ALTER SESSION, ALTER SYSTEM |
| Modifiable in a PDB | Yes |
| Basic | Yes |
•DB_CREATE_ONLINE_LOG_DEST_n 其中n = 1,2,3，… 指定oracle管理的控制文件和在线重做日志的默认位置
| Property | Description |
| Parameter type | String |
| Syntax | DB_CREATE_ONLINE_LOG_DEST_[1 |
| Default value | There is no default value. |
| Modifiable | ALTER SESSION, ALTER SYSTEM |
| Modifiable in a PDB | Yes |
| Basic | Yes |
•DB_DOMAIN 在分布式数据库系统中，DB域指定数据库在网络结构中的逻辑位置
| Property | Description |
| Parameter type | String |
| Syntax | DB_DOMAIN = domain_name |
| Default value | There is no default value. |
| Modifiable | No |
| Modifiable in a PDB | Yes |
| Range of values | Any legal string of name components, separated by periods and up to 128 characters long (including the periods). |
| Basic | Yes |
| Oracle RAC | You must set this parameter for every instance, and multiple instances must have the same value. |
•DB_NAME 指定最多8个字符的数据库标识符
| Property | Description |
| Parameter type | String |
| Syntax | DB_NAME = database_name |
| Default value | There is no default value. |
| Modifiable | No |
| Modifiable in a PDB | No |
| Basic | Yes |
| Oracle RAC | You must set this parameter for every instance. Multiple instances must have the same value. |
•DB_RECOVERY_FILE_DEST 指定快速恢复区域的默认位置
| Property | Description |
| Property | Description |
| Parameter type | String |
| Syntax | DB_RECOVERY_FILE_DEST = directory |
| Default value | There is no default value. |
| Modifiable | ALTER SYSTEM ... SID='*' |
| Modifiable in a PDB | No |
| Basic | Yes |
| Oracle RAC | You must set this parameter for every instance, and multiple instances must have the same value. |
•DB_RECOVERY_FILE_DEST_SIZE 以字节为单位指定在快速恢复区域中创建的目标数据库恢复文件使用的总空间的限制
| Property | Description |
| Parameter type | Big integer |
| Syntax | DB_RECOVERY_FILE_DEST_SIZE = integer [K |
| Default value | 0 |
| Modifiable | ALTER SYSTEM ... SID='*' |
| Modifiable in a PDB | No |
| Basic | Yes |
| Oracle RAC | You must set this parameter for every instance, and multiple instances must have the same value. |
•DB_UNIQUE_NAME 为数据库指定全局惟一的名称
| Property | Description |
| Parameter type | String |
| Syntax | DB_UNIQUE_NAME = database_unique_name |
| Default value | Database instances: the value of DB_NAME |
| Oracle Automatic Storage Management instances: +ASM | |
| Modifiable | No |
| Modifiable in a PDB | No |
| Basic | Yes |
| Oracle RAC | Multiple instances must have the same value. |
•INSTANCE_NUMBER 为使用存储参数FREELIST组创建的每个数据库对象指定一个惟一的编号，该编号将实例映射到一个空闲列表组
| Property | Description |
| Parameter type | Integer |
| Default value | 0 (zero) |
| Modifiable | No |
| Modifiable in a PDB | No |
| Range of values | 1 to maximum number of instances specified when the database was created |
| Basic | Yes |
| Oracle RAC | You must set this parameter for every instance, and all instances must have different values. |
•LDAP_DIRECTORY_SYSAUTH 允许或不允许授予管理权限的用户基于目录的授权，如SYSDBA、SYSOPER、SYSBACKUP、SYSDG和SYSKM
| Property | Description |
| Parameter type | String |
| Syntax | LDAP_DIRECTORY_SYSAUTH = { yes |
| Default value | no |
| Modifiable | No |
| Modifiable in a PDB | Yes |
| Basic | Yes |
•LOG_ARCHIVE_DEST_n 初始化参数最多定义31(其中n = 1,2,3，…31)目的地，每个目的地必须指定位置或服务属性，以指定在何处存档重做数据
| Property | Description |
| Parameter type | String |
| Default value | There is no default value. |
| Modifiable | ALTER SESSION, ALTER SYSTEM |
| Modifiable in a PDB | No |
| Basic | Yes |
•LOG_ARCHIVE_DEST_STATE_n 参数(其中n = 1,2,3，…31)指定对应目的地的可用状态
| Property | Description |
| Parameter type | String |
| Default value | enable |
| Modifiable | ALTER SESSION, ALTER SYSTEM |
| Modifiable in a PDB | No |
| Basic | Yes |
•NLS_DATE_LANGUAGE 将该语言用于日、月名称和日期缩写词的拼写。由TO_DATE和TO_CHAR函数返回
| Property | Description |
| Parameter type | String |
| Syntax | NLS_DATE_LANGUAGE = language |
| Default value | Derived from NLS_LANGUAGE |
| Modifiable | ALTER SESSION |
| Modifiable in a PDB | Yes |
| Range of values | Any valid NLS_LANGUAGE value |
| Basic | No |
•NLS_TERRITORY 指定要遵守日期和星期编号公约的区域的名称
| Property | Description |
| Parameter type | String |
| Syntax | NLS_TERRITORY = territory |
| Default value | Operating system-dependent |
| Modifiable | ALTER SESSION |
| Modifiable in a PDB | Yes |
| Range of values | Any valid territory name |
| Basic | Yes |
•OPEN_CURSORS 指定一个会话一次可以拥有的最大打开游标数(对私有SQL区域的句柄)。您可以使用此参数来防止会话打开过多的游标
| Property | Description |
| Parameter type | Integer |
| Default value | 50 |
| Modifiable | ALTER SYSTEM |
| Modifiable in a PDB | Yes |
| Range of values | 0 to 65535 |
| Basic | Yes |
•PGA_AGGREGATE_TARGET 指定附加到实例的所有服务器进程可用的目标聚合PGA内存
| Property | Description |
| Parameter type | Big integer |
| Syntax | PGA_AGGREGATE_TARGET = integer [K |
| Default value | 10 MB or 20% of the size of the SGA, whichever is greater |
| For a PDB | the default value is the same as the CDB's default value. |
| Modifiable | ALTER SYSTEM |
| Modifiable in a PDB | Yes |
| Range of values | Minimum: 10 MB |
| Maximum: 4096 GB - 1 | |
| Basic | Yes |
•PROCESSES 指定可以同时连接到Oracle的操作系统用户进程的最大数量
| Property | Description |
| Parameter type | Integer |
| Default value | The value is derived, and it typically depends on the number of cores reported in the alert log. |
| Modifiable | No |
| Modifiable in a PDB | No |
| Range of values | 6 to operating system dependent |
| Basic | Yes |
| Oracle RAC | Multiple instances can have different values. |
•REMOTE_LISTENER 指定一个网络名称，该名称解析为Oracle Net远程侦听器的地址或地址列表(即与此实例不在同一系统上运行的侦听器)。地址或地址列表在TNSNAMES中指定，或为您的系统配置的其他地址存储库
| Property | Description |
| Parameter type | String |
| Syntax | REMOTE_LISTENER = network_name |
| Default value | There is no default value. |
| Modifiable | ALTER SYSTEM |
| Modifiable in a PDB | Yes |
| Basic | Yes |
•REMOTE_LOGIN_PASSWORDFILE 指定Oracle是否检查密码文件
| Property | Description |
| Parameter type | String |
| Syntax | REMOTE_LOGIN_PASSWORDFILE = { shared |
| Default value | exclusive |
| Modifiable | No |
| Modifiable in a PDB | No |
| Basic | Yes |
| Oracle RAC | Multiple instances must have the same value. |
•SESSIONS 指定可以在系统中创建的最大会话数
| Property | Description |
| Parameter type | Integer |
| Default value | Derived: (1.5 * PROCESSES) + 22 |
| Modifiable | ALTER SYSTEM can be used in a PDB only to change the value of the SESSIONS parameter for that PDB. |
| Modifiable in a PDB | Yes |
| Range of values | 1 to 216 (which is 1 to 65536) |
| Basic | Yes |
•SGA_TARGET 指定所有SGA组件的总大小
| Property | Description |
| Parameter type | Big integer |
| Syntax | SGA_TARGET = integer [K |
| Default value | 0 (SGA autotuning is disabled for DEFERRED mode autotuning requests, but allowed for IMMEDIATE mode autotuning requests) |
| Modifiable | ALTER SYSTEM |
| Modifiable in a PDB | Yes |
| Range of values | 64 MB to operating system-dependent |
| Basic | Yes |
•SHARED_SERVERS 指定启动实例时要创建的服务器进程的数目。如果系统负载降低，则维护服务器的最小数量。因此，您应该注意不要在系统启动时将共享服务器设置得过高
从Oracle Database 12c Release 1(12.1.0.2)开始，可以在PDBs上设置共享服务器参数。但是，与可以在PDB上设置的大多数其他参数不同，此参数只能在PDB中使用，以启用或禁用对该PDB的共享服务器的使用。因此，在PDB中，DBA可以将共享服务器设置为0来禁用该PDB的共享服务器，或者使用ALTER SYSTEM RESET共享服务器来重新启用该PDB的共享服务器。为CDB配置共享服务器只能在根目录中完成
| Property | Description |
| Parameter type | Integer |
| Default value | If you are using shared server architecture or if the DISPATCHERS parameter is set such that the total number of dispatchers is more than 0, then the default value is 1. |
| Modifiable | ALTER SYSTEM |
| Modifiable in a PDB | Yes |
| Range of values | The value of this parameter should be less than MAX_SHARED_SERVERS. If it is greater than or equal to MAX_SHARED_SERVERS, then the number of servers will not be self-tuned but will remain constant, as specified by SHARED_SERVERS. |
| Basic | Yes |
•STAR_TRANSFORMATION_ENABLED 确定是否将基于成本的查询转换应用于星型查询
| Property | Description |
| Parameter type | String |
| Syntax | STAR_TRANSFORMATION_ENABLED = { FALSE |
| Default value | FALSE |
| Modifiable | ALTER SESSION, ALTER SYSTEM |
| Modifiable in a PDB | Yes |
| Basic | Yes |
•UNDO_TABLESPACE 指定实例启动时使用的撤消表空间。如果在实例处于手动撤消管理模式时指定了此参数，则会出现错误，启动将失败
| Property | Description |
| Parameter type | String |
| Syntax | UNDO_TABLESPACE = undoname |
| Default value | The first available undo tablespace in the database. |
| Modifiable | ALTER SYSTEM |
| Modifiable in a PDB | Yes |
| Range of values | Legal name of an existing undo tablespace |
| Basic | Yes |
| Oracle RAC | Each instance must have a unique value for this parameter, when it is set. |
