Database Administrator

Environment: DB: 11.2.0.2 rac OS: RHEL 5.6 The following problems are encountered when upgrading a single machine to RAC under Oracle 11gR2 today. [Oracle @ 11rac5 ~] $ Sqlplus/as sysdba   SQL * Plus: Release 11.2.0.2.0 Production on Tue Oct 9 19

Oracle Import utility allows you to extract data from a database and write the data to an operating system file. The basic format used by imp: imp [username [/password [@ service]. The following describes common usage of imp. 1. Get help Imp help =

During the 11th holiday, it may not be easy. If the database reports an error and a critical business cannot be properly executed on a certain day, it must be processed immediately. Cause Analysis 1, log on to the database, view the host log, the

Oracle queries user policiesSelect username, profile from dba_users; Generally, the user's policy name is "DEFAULT" Queries a user's specific policies Select × from dba_profiles where profile = 'default '; SQL> select * from dba_profiles where

Under multiple instances: You can bind a cpu to prevent mutual interference between multiple instances. Mongodb memory can also be restricted to the master to prevent all memory occupied by one instance. Ulimit-s 4096 & ulimit-m 31457280 & sudo-u

1. view the storage engines supported by the system Show engines; 2. view the storage engine used by the table Two methods: A. show table status from db_name where name = 'table _ name '; B. show create table table_name; If the display format

Installation version: mysql-5.5.27.tar.gz 1. Install the cmake compiler. 1) download cmake # Cd/usr/local/src # Wget http://www.cmake.org/files/v2.8/cmake-2.8.3.tar.gz 2) decompress cmake # Tar-zvxf cmake-2.8.3.tar.gz 3) Configure Compilation # Cd

Due to the rapid growth of data in the Oracle database, the disk space of the data file is insufficient. To clean up the space, I disabled oracle, then, the data files, control files, and redo log groups are moved directly to another disk, but this

Dblink is a database object that allows you to access remote tables and execute remote programs. In addition, dblink is a one-way connection. When dblink is created, Oracle records its metadata in the data dictionary. In db link, you must consider

The customer refreshed the materialized view today ORA-04062 \ ORA-04068 error, colleagues handled this problem, the following record the process: OS: aixDB: 9.2.0.8 The database where the base table of the materialized view is located has

When the jdbc interface is provided in the hibernate project, the problem that only the first character can be obtained when querying data in the database char field is found. The solution code is as follows: Package com. newer. common; Import java.

Operating system version: rhel5.5Oracle Client Version: 10g64-bitClient: http://www.oracle.com/technetwork/topics/linuxx86-64soft-092277.html 1. Find the corresponding version, download the following file, and install it. Install basic first, and

I. header files When introducing the header file of the informix database, you can use the following method: Exec SQL INCLUDE sqlca;Exec SQL INCLUDE sqlda;Exec SQL INCLUDE sqlhdr;Exec SQL INCLUDE decimal;Exec SQL INCLUDE locator;Exec SQL INCLUDE

-- SQL deletes the primary keys of all user data tables in the database. -- Query all constraints of the current database before deletionSelect * from information_schema.key_column_usage Declare @ TableName nvarchar (250)-- Declare that the cursor

When the password of an Oracle Database User contains special characters such as @, the user can directly use the normal password for input. the login fails because oracle resolves the characters After @ into the network service name. In the

There are two problems with uninstalling the Oracle Al Installer that comes with Oracle: 1) Slow speed; 2) not clean; not completely; there are some residual registries that will affect subsequent installation. Therefore, we recommend that you

Problem: when using an implicit cursor like select into from tablename, if no data is found, an error in the ora-01403 is reported. Each time an explicit cursor is used, it is very troublesome to open the value. An experienced instructor suggested

According to Oracle Net, the database server may also be a client, because tnsnames. ora can have a server description. That is, only the listener will always be a server. Instance: Listener = n: m (I) benefits of dual listeners: ① Client

Recurrence The problem that a colleague encountered when performing a data dump is simplified as follows: 1. Create a table Drop table if exists tb; Create table tb ( C timestamp not null default '2017-00-00 00:00:00' ) ENGINE = InnoDB default

System Environment: CentOS 6.3 X86_64 Redis Introduction Redis is essentially a Key/Value database, similar to the NoSQL database of Memcached, but its data can be stored persistently on the disk, solving the problem of no data loss after service