Database Administrator

I. SQLITE operations SqliteProvides some C function interfaces that you can use to operate databases. By using these interfaces, you can pass some standard SQL statements (in char * type) to the sqlite function, and sqlite will operate the database

The master-slave synchronization of mysql fails. the following error is reported in the log:120309 18:39:23 [Note] Slave SQL thread initialized, starting replication in log 'mysql-bin.000004 'at position 2207467, relay log'./mysqld-relay-bin.000011'

**************************************** ******* Oracle database instance startup and Shutdown Process **************************************** ******* The Oracle database instance should be started strictly. The database is only loaded after the

1. Introduction 1. Index: (1) A table-independent schema object that can be stored in a disk or tablespace different from the table (2) If an index is deleted or damaged, it does not affect the table. Only the query speed is affected. (3) once an

Usage and exceptions of optical mark in Oracle 1. Use of cursor without Parameters SQL>Declare 2CursorClIs Select*FromEmp; 3 emp_row emp % rowtype; 4Begin 5OpenCl; 6 loop 7FetchClIntoEmp_row; 8 exitWhenCl % notfound; 9

During the use of Oracle tables, some additional columns in the actual table are called pseudo columns. Pseudo columns are like columns in a table, but they are not stored in the table. Pseudo columns can only be queried, but cannot be added,

The previous article on how to store Distributed Data Based on MongoDB describes how to store Distributed Relational Data Based on Mongodb. Although it can be queried in a common way, we will introduce how to use the MapReduce function provided in

Steps for creating a manual Oracle database: 1. directories required for creating databases, including data file storage directories, log storage directories, and archive storage directories.2. Create a password file3. Create a parameter file4. Use

Select column into t_prop... If no value is found, an error is returned. The processing method is as follows: Use Aggregate functions, such: Create Or Replace ProcedureTestIs T_prop varchar2 (20 ); Begin

[Oracle @ Template-RedHat54 admin] $ lsnrctl LSNRCTL for Linux: Version 11.2.0.1.0-Production on 13-APR-2012 23:09:14 Copyright (c) 1991,200 9, Oracle. All rights reserved. Welcome to LSNRCTL, type "help" for information. LSNRCTL> statusConnecting

My dear friends, let's discuss PostgreSQL and some of the most useful extensions of the database today. PostgreSQL is a relational database management system with the following features: The Database supports almost unlimited sizes; Powerful and

When MySQL Workbench is used for batch database update, the following error message is displayed when you execute a statement: Error Code: 1175You are using safe... without a WHERE that uses a KEY column   Because it is the default security

Oracle's rownum is a pseudo-column, and its principle has a lot to do on the net, but we are still very confused. In fact, we just need to understand its principle. What's important is to use it, therefore, we only need to ensure that we do not make

Summary The data storage method has a great impact on the overall performance of the application. Is Data Access smooth or random? Are data stored on disks and stored on flash cards? Does multi-threaded read/write affect performance? How can we

Partitions by the range of values of one or more columns in a table.Syntax: PARTITIONBYRANGE (column_name) ( PARTITION part1 value less than (range1 ), PARTITION part2 value less than (range2 ), ... [PARTITION partN value less than (MAXVALUE)]

Oracle uses SQL statements to implement the desc function: Select a. COLUMN_NAME field name,DATA_TYPE | DECODE (DATA_TYPE, 'date', '', 'clob','', 'blob ', '', 'bfile','', 'float ', '', 'long raw','', 'long', '', 'raw ',' ('| TO_CHAR (DATA_LENGTH) | '

In general, we use visual tools such as pl SQL DEVELOPER and TOAD to develop and debug Oracle stored procedures. No one is stupid enough to use vim for development and SQL plus for debugging. But in some cases, we know how to debug the stored

Basic table operations The table has a name. A table consists of rows and columns. A table is the most basic object for storing data. We call a common tableHeap table(Heap table), which means storing data in disorder. Heap table is an important part

Source end hp-unix + Oracle10g-r204-rac, target end RedHat + oracle10g.When network_link is used for export on the target end, the following error is returned:Rm/opt/oradir/expdp. dmpExpdp \ "sys/oracle as sysdba \" directory = oradir network_link =

1. determine the user's instance flag (DB_NAME and SID ). The racle instance flag is hidden from the Database Name (DB_NAME). This instance flag is used to avoid confusion with other Oracle instances. Other Oracle instances mentioned here can be