今天通过视频学习，和网上搜索总结了一些oracle 常用的动态性能视图和大家分享
要查看oralce有哪些可用的动态性能视图可以看v$fixed_table
1.关于数据库/实例的动态性能视图
v$database :displays information about the database from the control file.
v$instance :displays the state of the current instance(当前实例的状况)
v$option ：displays oracle database options and features(数据库的选项和特性)
：option must be separately licensed(选项单独认证设置)
：whereas features come with the product and are enabled based on
the product that is running(产品特性的发挥也是要产品运行才能体现)
v$parameter ：displays information about the initialization parameter that
:are currently in effect for the session.A new session inherits
:parameter values from the instance-wide values displayed by the
:v$system_parameter view.
v$backup :display the backup status of all online datafiles.(所有在线数据文件的备份情况)
v$px_process_sysstat ：contains information about the sessions running parallel execution
(包含并行执行会话的信息)
v$process ：displays information about the currently active processes(活动进程的信息)
v$waitstat: displays block contention statistics.this table is only updated when timed
:statistics are enabled(显示热块竞争的统计，当时间统计参数启动时，这个表只能更新）
v$system_event ：total waits for an event(事件的总等待时间)
2.关于磁盘文件的视图
v$datafile :datafile information from the control file
v$filestat :displays the number of physical reads and writes done and the total number of
:single-block and multiblock I/Os done at file level(在文件级别显示物理读写和io信息）
v$log ：displays log file information from the control file
v$log_history :log history information from the control file
v$dbfile :all datafiles making up the database
v$tempfile :tempfile information
v$tempstat :file read/write statistics(文件读写的统计)
v$segment_statistics ：segment-level statistics
3.contention竞争的视图
v$lock :lists the locks currently held by the oracle database and outstanding requests for
: a lock or latch (正在使用的锁和过多的请求对锁）
v$rollname ：lists the names of all online rollback segments(在线回滚段的信息)
v$rollstat ：contains rollback segment statistics（回滚段的统计情况）
v$waitstat ：block contention statistics(块争用统计)
v$latch ：aggregate latch statistics (闩锁的总和统计)
4.memory 的视图
v$buffer_pool_statistics :statistics about all buffer pools available for the instance
:(实例所有可用的缓存池的统计)
v$db_object_cache：database objects thatare cached inthe library cache(被缓存在库缓存区的对象)
v$librarycache ：contains statistics about library cache performance and activity
(库缓存区的性能和活动的统计信息)
v$rowcache ：statistics for data dictionary activity(数据字典活动信息统计)
v$sysstat：system statistics
v$sgastat :detailed information on the system global area（sga）
5.用户/会话的视图
v$lock :lists the locks currently held by the oracle database and outstanding requests for
: a lock or latch (正在使用的锁和过多的请求对锁）
v$open_cursor :list cursors that each user session currently has opened and parsed,or cached
(当前会话打开的游标列表)
v$process ：displays information about the currently active processes(活动进程的信息)
v$transaction ：lists the active transaction in the system (列出系统活动的事物)
v$px_sesstat ：parallel execution(px),contains information about the sessions running
(正在执行会话的并行执行情况统计)
v$px_session ：parallel execution(px),contains information about the sessions running
v$sesstat ：user session statistics
v$session_event :on waits for an event by a session(会话等待事件)
v$sort_usage ：在11g好像就没有了
v$sort_segment:displays information about every sort segment in given instance
显示实例中给出的每个回滚段的信息。
v$session_wait ：current or last wait for each session(当前或上次的等待信息)
v$session
v$session_object_cache ：object cache statistics for the current user session on the local
:server(instance)
