Database Administrator

Differences between user, user account, and schema A user isa person who connects to a user account by establishing a session against theinstance and log on with the user account name A schemais a set of objects owned by a user account. User Account

Summary of Oracle transmission tablespace migration data Note: users must be created before the tablespace is migrated. Otherwise, the migration will fail. Sometimes, we need to migrate relatively large data across platforms (10 Gb supports

Back up archived logs -- View the archive logs generated by the first archive location in the past day. dest_id indicates the location where archive logs are stored, corresponding to 1 ~ in v $ archive_dest ~ The value of the destination field of 10.

1. Get 00:00:00 of the current day Select TRUNC (SYSDATE) FROM dual; 2. Get 23: 59: 59 seconds on the current day (add one day and then minus one second on the basis of 00:00:00 on the current day) Select trunc (SYSDATE) + 1-1/86400 FROM dual; 3.

Restore: restore recover recoveryFirst use the restore database command to restore to the backup point through the backup file, and then use the recover database command to restore to the time point when the media is damaged through the archive log

Recovery Type1. Time-based recovery2. sequence-based recovery3. SCN-based recovery Recovery Process:1. mount the database2. Allocate multiple channels for concurrency3. Restore all data files4. Restore the database with until time, until sequence,

MongoDB provides the Replica pairs mode to start the database. After the database is started in this mode, the database automatically negotiates who is the master and who is the slave. Once a database server loses power, the other server

There is a MySQL database with more than 1.1 billion records because of its working relationship. I thought that the query performance of the MyISAM engine would exceed InnoDB. I tried it these two days, but because the data volume is too large, the

To eliminate the connection problem between the client and the server, first check whether the client configuration is correct (the client configuration must be consistent with the database server listening configuration), and then solve the problem

   Declare CursorMy_curIs SelectEmpno, deptnoFromEmp; Employee_id emp. empno % type; Dept_id emp. deptno % type; Begin OpenMy_cur; FetchMy_curIntoEmployee_id, dept_id; While my_cur % found loop

What to do before the transaction is committed Before submitting a transaction, Oracle must do the following: ① Remember what the data looks like before it is modified ② Remember what data will be changed soon ③ Remember the association between

RDA full name RemoteDiagnostic Agent is a tool used by Oracle to collect and analyze databases. However, the statistical information is far greater than that of databases, it can also be said that the information of an Oracle db server that an

Sequence usage in Oracle: Create table test(Pid integer primary key,Name varchar (20));Select * from test;Insert into test values (1, 'jack ');Create sequence test_seq; -- create a sequenceSelect test_seq.nextval from dual; -- add one after each use

1. Go to the official website of Apple to download and support your system JAVA. You need to install the Lion system separately. Snow Leopard comes with JAVA and only needs to update the new version. The address is this

1. Overview Oracle introduces Redo log for data recovery Related Oracle processes: redo the log write process (LGWR) Related data dictionaries v $ log, v $ logfile Author permission: sys, system permission 2. View redo log information View redo log

SQL>Lock table state in exclusive mode; Table (s) Locked. SQL>Insert into state (state_cd, state_name) values ('nm ', 'neimenggu '); 1 row created. SQL>Select * from state; STAT STATE_NAME ---------------------------------- AZ Arizona

In Oracle 10 Gb, if we did not select an installation example when creating an instance, we can also create it using the script under $ ORACLE_HOME/demo/schema after creating the instance. For details about the creation method, the official

I. creation process Create Or Replace ProcedureP_rebuild_all_index(Tablespace_nameIn Varchar2)AsSqltVarchar(200);BeginForIdxIn(SelectIndex_name, tablespace_name, statusFromUser_indexesWhereTablespace_name=Tablespace_nameAndStatus='VALID' And

An error occurred while importing the exp logical backup file to the standby database. The error message is as follows: IMP-00017: The following statement failed due to Oracle error 6550: "Declare srec DBMS_STATS.STATREC; begin srec. MINVAL: = '00

Summary:Direct path insertion directly allocates space outside the high waterline, bypasses the data buffer, and directly inserts data into the data file where the table is located.Direct path insertion does not generate Redo and Undo logs and