DBA used SQL database of basic information

First part: 

1 . See oracle maximum number of connections   

　　SQL > Show Parameter Processes   

　　# The maximum number of connections 

 2 modify the maximum number of connections.   

　　SQL > ALTER System SET Processes = value scope = SPFILE   

　　　restart the database   

　　SQL > the shutdown Force SQL> Start Force 

 . 3 view the current. connections   

　　SQL > the SELECT * from v $ the session the WHERE username iS not null 

 4 . Check connections of different users   

　　SQL > the SELECT username, cOUNT (username) from v $ the session the WHEREusername IS Not null Group by username 

　　# view a specified user connections 

 5 . connections See active   

　　SQL > SELECT COUNT (*) from V $ the session WHERE Status = ' Active '  

　　# View concurrent connections 

 6 . See specified program is connected number   

　　SQL > SELECT COUNT (*) from V $ the session WHERE Program = ' jdbc Thin Client ' 

　　# Check number of oracle jdbc connection 

 7 . See installation database instance (dba permissions)   

　　SQL > SELECT * from V $ instance 

 . 8View running instance name   

　　SQL > Show the Parameter instance_name 

 9 . View the database name   

　　SQL > Show the Parameter db_name 

 10 . View the database domain name   

　　SQL > Show the Parameter db_domain 

 11 . View the database service name   

　　SQL > Show the Parameter SERVICE_NAMES 

 12 . Check global database name   

　　SQL > Show the Parameter , Ltd. Free Join 

 

part II: 

1 , should first understand the current version of the Oracle database and platform and related information 
   this is very important, busy for a long time yet know which version of your database, running on what system, it would be very sad, so I personally think that this is the first step you need to know. The following script can help you get information you need. 
   the SELECT * from v $ Version;
    the SELECT * fromdba_registry_database;
    SELECT the dbid, name, open_mode, database_role, PLATFORM_NAME from V $ instance;
    SELECT dbms_utility.port_string from Dual; 

   SET SERVEROUTPUT ON 
   DECLARE 
     Ver VARCHAR2 ( 100 ); 
     compat VARCHAR2 ( 100 ); 
   the begin 
     dbms_utility.db_version (Ver, compat); 
     dbms_output.put_line ( ' Version: ' || || ver ' Compatible: ' || compat); 
   End;
    /
 2 , secondly to understand your database which components are installed
    select* From dba_registry; 
　
3 , understand this is a stand-alone or clustered environment? 
   The judge many ways, I am here to give a method to determine the dbms_utility aid. 
   SET SERVEROUTPUT ON 

   DECLARE 
     inst_tab dbms_utility.instance_table; 
     inst_cnt NUMBER; 
   the begin 
     IF dbms_utility.is_cluster_database the then 
        dbms_utility.active_instances (inst_tab, inst_cnt); 
        DBMS_OUTPUT.PUT_LINE ( ' - ' || inst_tab.FIRST); 
        DBMS_OUTPUT.PUT_LINE (the TO_CHAR (inst_cnt)) ; 
     the else 
        DBMS_OUTPUT.PUT_LINE ( ' Not A' Clustered Database ' ); 
     End IF; 
   End;
    /
 4 , configured with the DataGuard?
    The SELECT Protection mode, protection_level, remote_archive, database_role, dataguard_broker, guard_status
    from v $ Database;
 5 , whether hired a filing mode? 
   conn / AS sysdba 
   Archive log List; 
   the SELECT log_mode from v $ Database; 
　
6 , whether hired a flashback database feature?
   the SELECT flashback_on from v $ Database; 
   if it is, then check the configuration of the FRA 
7 , whether hired a force logging and supplemental logging?
   selectforce_logging, supplemental_log_data_min, supplemental_log_data_pk, supplemental_log_data_ui, 
          supplemental_log_data_fk, supplemental_log_data_all 
   from v $ Database;
 8 , Understanding the control files that make up
    the SELECT * from v $ controlfile;
 9 , to understand the log files that make up
    the SELECT l.group #, lf.type, lf.member , l.bytes, l.status LOG_STATUS, lf.status LOGFILE_STATUS
    from V $ log L, V $ logfile LF
    WHERE l.group # = lf.group # 
   Order by . 1 , . 3 ;
 10 , understand the composition and location of the parameter file 
    show SPFILE the Parameter 
    the Create SPFILE from... pfile 
    the Create pfile from SPFILE; 
    the Create SPFILE from Memory; 
    the Create pfile from Memory;
 11 , understand the instance of information
     the SELECT instance_name, host_name, Status, Archiver, database_status, instance_role, active_state
     from v $ instance;
 12 , user and password Related 
    whether to use the default password? 
    Are you using Profile ? 
    Are hired a password verification function? 
    User authentication method? 
    The password is case sensitive and so on. 
    SELECT name, value from GV $ Parameter WHERE name = ' RESOURCE_LIMIT ' ;
    select profile, resource_name, limit from dba_profiles order by 1,2;

    select username, profile from dba_users where account_status = 'OPEN' order by 1;
　
    select d.username, u.account_status
    from dba_users_with_defpwd d, dba_users u
    where d.username = u.username and account_status = 'OPEN' 
    order by 2,1;
　
13、是否打开了BLOCK CHANGE TRACKING
    selectfilename, Status, bytes from v $ BLOCK_CHANGE_TRACKING;
 14 , only use those characteristics (the Feature)? 
    DBMS_FEATURE_USAGE_REPORT 
　
15 planning, table spaces and data files 
    that you are familiar with, do not write 
　
16 , character sets associated
     the SELECT * from DATABASE_PROPERTIES; 
　
17 , whether an object exist in the system invalid
     SELECT owner, object_type, COUNT (* )
     from dba_objects
     WHERE Status = ' iNVALID ' 
    Group by owner, object_type; 
18 is , further 
    whether the ASM using? 
    What is the current backup methods and strategy system is? 
    Network configuration file is how? 
　
19, Look at the recent alert log to get some useful information
 20 , ran several performance analysis report to see how the system operational status of the latest
 21 , ran a RDA report, collection complete system status report 

22 , see RMAN backup schedule 

select SID, 
       Serial #, 
       context, 
       SOFAR, 
       TOTALWORK, 
       round (SOFAR / TOTALWORK * 100 , 2 ) " % Complete " 
  from V $ SESSION_LONGOPS
  WHERE opname like ' the RMAN:% ' 
   and the NOT opname the lIKE ' the RMAN: Aggregate% ' ;