Database Administrator

Prepare a table EmployeeTable: EMPL EMPLOYEE_NAME DEPARTMENT_ID ------------------------------------- 1001Jack1 1002Tom2 1003Smith2 1004Rose3 DepartmentTable: DEPARTMENT_ID DEPARTMENT_NAME DEPARTMENT_LOCATION ------------------------------

Mysql has multiple instances. The datadir, pid, port, and socket of each instance should be different. I. Foundation, very important Each instance should configure the my. cnf file under its own datadir.First, let's talk about the search sequence of

01. query all data in the employee table and describe the disadvantages of using * Select * from emp; 01. query the salaries of employees whose job is 'President' Select sal from emp where job = 'President '; 02. query the information of employees

Oracle 10 Gb has provided the recycle bin function similar to windows. When you delete a table, it is not directly deleted, but moved to the recycle bin. If you need to retrieve the original table from the recycle bin, you can use flashback to

Leading hint indicates that Oracle uses the table specified in leading as the driving table,For example, the normal access plan is as follows:SCOTT@www.bkjia.com> select e. ename, hiredate, B. comm2 from emp e, bonus B3 where e. ename = B.

I. Physical backup tool rman (Recovery Manager) Rman features are powerful and operations are relatively complicated. For common developers, it is generally not required to use it in their daily work. interested colleagues can view Oracle-related

This error is the most common error in Oracle db, which is caused by many reasons. However, one of the major reasons is that the database server suddenly loses power and then restarts the database to report an error.The cause of this problem is that

Keywords: Oracle to_char, to_number, and to_date usage TO_CHAR converts a date or number to a string.TO_DATE converts a string to a date type conversion function in the database.TO_NUMBER converts a character to a number TO_CHARUse the TO_CHAR

Environment: PLSQL Developer 7.1.5 Oracle 11.2.0 Oracle does not specify an auto-increment column as MYSQL or MSSQLServer does. However, in Oracle, the SEQUENCE can be used to automatically increase fields. In Oracle, SEQUENCE is called a SEQUENCE.

I. Reasons for triggering this error and Related Factors This is because "PASSWORD_LIFE_TIME = 180 days" is set in the default profile in Oracle 11g by default.The password has expired. Ii. Error: After the user is locked, A ORA-28000 error is

The control file records important information about the DATABASE, including the DATABASE identifier (the DB_NAME parameter or the name used when the create database statement is used) name and location of data files and redo log files, timestamp of

Create Table, prompting ORA-00959: tablespace 'mc _ data' does not exist. First, confirm the current user's tablespace. Select username, default_tablespace, temporary_tablespace from dba_users where username = 'mcmidyl '; The default tablespace

Partition maintenance operations include:Add PartitionDelete PartitionPartition TruncationMerge partitionsShard1. Add a partition-Add a new partition after the last partition ALTER TABLESALESADDPARTITION P4VALUESLess than (4000 ); 2. delete a

On Friday, April 6, a server time was synchronized. Who could have neglected to write April 6 as June 6? After all the machine time synchronization, I found that I had corrected the mistake and made changes quickly, log on to the database and check

In Oracle's Data Guard environment, the logical standby database application process stops and the log shows an error as ORA-01403 not data found. The specific information is as follows: Mon May 21 10:39:31 2012 LOGSTDBY status: ORA-01403: no data

I. Prerequisites for Migration:1. The operating system meets the installation conditions of the Oracle database version.2. database versions are consistent 2. operations on the source database: 1. Check whether the database is archived. If not,

This is a real customer demand implementation solution. The customer needs to monitor the time periods, users, applications, and access records of some key tables. The database system is Oracle9.2.0.1. Its audit function can meet this

CouchDB is very easy to implement distributed data replication. We only need to send the POST request to the specified database_ ReplicateThe request Body is a JSON string. Wiki.apache.org/couchdb/Replication To continue copying, you only need to

Create a new user in Oracle, and create a new schema to distinguish other directories. At the same time, it also saves data objects of all related users and tables of users. How to create a new user? (Create a new db) First, use the system (default

Connect to Oracle with Java, run a period of time, the Program reported an error, connection failed, ora-28000 the account is locked, this reason is because the user is locked, generally this situation, there are several reasons: 1. The reason is