Oracle schema object

1. Static data dictionary view classification
user_: All object information owned by the current user
all_: The current user can access all object information and permission information
dba_: All objects and permission information owned by the database

  object: object ,tables: form ,tab_columns: Each column of the table ,views: View ,role_privs: jurisdiction ,users: User information and so on

2： Dynamic performance data dictionary view （V$）
The overview view ：V$FIXED_Table
The definition view ：V$FIXED_VIEW_DEFINITION
Common dynamic performance views
v$controlfile: Control file list
v$database: database information
v$datafile: Data file information
v$log: Log file information
v$instance： Current instance status
v$parameter: Memory parameter information
v$session: Current session information
v$sga:sga Information
v$spparameter:Spfile Parameter information of the file , If the file is not used to start the instance , Then try all isspecified yes false
v$tablespace: Tablespace information
v$thread: Thread information
v$version: Version information

3: Build table
create table table_name( Attribute example )
[tablespace tablespace_name]
[cluster cluster_name( Attribute example )]
[pctfree integer]（default 10）
[pctused integer]
[initrans integer]
[maxtrans integer]
[recoverable|unrecoverable]
[storage storage_cause]
[logging|nologging]
[cache|nocache]

pctfree: Percentage of space reserved in the block （ To increase the length of the line （update operation ）, When there is not enough space left in the express pctfree when ,        Do not add new lines to the block , here insert Operation is not allowed ）
pctused: Minimum percentage of space used within a block （ Data can only be written when the space utilization in the cache is lower than what ）
initrans: Specify the initial value of the transaction item allocated to each data block in the table
maxtrans: Specify the number of transactions that can modify table data blocks at the same time
recoverable/unrecoverable: Whether the table is repairable
logging/nologging: Whether to create and modify the table （ Include the data in the table ） Record in the redo log
cache: Specifies that even when performing a full table scan , The blocks retrieved for this table will also be placed in the buffer cache LRU The most recently used end of the list      （ When a table is small , When users visit frequently, they can use ）
nocache: and cache contrary

 

4: Build clusters cluster
Cluster table ： Tables that share the same set of columns , The data shared by the cluster table is stored in the same data block , Not in the data row of each table
Step playing ：
   1： Build clusters
   2： Index the cluster
   3： Create a table on the cluster

create cluster cluster_name( Attribute example ) size integer[k|m]
[storage (storage_cause)]