Database Administrator

Query errors caused by corrupted MongoDB index files Problem description: When MongoDB is disabled abnormally, the index file may be damaged, and the data is not reflected in the index when the data is updated. Solution: Use scripts to recreate

Whether the Oracle database query object is locked and unlocked For details about whether the Oracle database object is locked, see the following SQL statement and the unlock process: -- Query the locked objects of the current userSelect B.

MySQL Single-host multi-instance Configuration Test environment: Operating System CentOS 6.4x86 MySQL 5.5.38 1. What is MySQL multi-instance? Multiple MySQL instances enable multiple service ports (such as 3306, 3307, and 3308) on one machine to run

Create an Oracle whitelist for RAC Due to business needs, you need to use a whitelist to restrict the addresses of users logging on to the database, and decide to use the database whitelist function! Generally, you only need to add the following

Implementation of udf row_number in Hive and problems encountered Add row_number for each piece of hive data. First, add the row number. You must consider that the data must be put in a reduce for execution. Code first Package xx. xxxxx. hive.

DB2 database backup script in Linux DB2 database backup script in Linux The script runs under the root user: The content of backupDB2Task. sh is as follows: Datedir = 'date + % Y-% m-% d'Delete_date = 'date + % Y-% m-% d -- date = '7 days

Use shell scripts to view database load In normal times, you may feel confused when viewing database problems. If no one gives feedback on the problem, you will not take the initiative to find the problem direction. awr, ash searches for relevant

Introduction to Oracle XML operations in various scenarios Recently, I have been studying Oracle PLSQL's series of XML operations. Combine the knowledge and references used in the work to sort out the following content: 1. How to generate an XML

Basics of SQLite Database 1. Introduction SQLite is an open-source embedded Relational Database Engine for SQL database with self-contained, zero configuration, and transaction support. It is highly portable, easy to use, compact, efficient, and

SQL Syntax of SQLite The SQLite library can parse most standard SQL languages. However, it also saves some features and adds some new features. This document attempts to describe the SQL syntax that SQLite supports/does not support. View the keyword

Error in mysqldump and error in mysqldump When you use the mysqldump command to back up the entire database, the following error is returned: Mysqldump: Couldn't execute 'show triggers like 'userlog'': Got error 28 from storage engine (1030) View

ADO. NET 5-delete a record using the Command object --- ShinePans, Source code: Using System; using System. collections. generic; using System. data; using System. data. sqlClient; using System. linq; using System. text; using System. threading.

Grouping statistics query (Chapter Summary) and grouping statistics chapter summary1. Five grouping functions are provided in SQL: COUNT (), AVG (), SUM (), MIN (), and MAX.2. The group by clause can be used to GROUP data, while the HAVING clause

Custom function programming in mysql and mysql Syntax: New: Create function function_name (parameter list) returns Return Value Type Function body Function name, which must be a valid identifier and should not conflict with an existing keyword. A

Petelai project experience small set (3) ___ from the Multi-table statistical amount to a table, petelai __ This project is mainly used by all departments and agents of petelai. The following function of this system is to collect agent fees. The

[Translated from mos] In 11gR2 rac environment, the file system usage is tight, and lsof shows many oraagent_oracle.l10 (deleted) and 11gr2rac In 11gR2 rac environment, the file system usage is tight, and lsof shows many oraagent_oracle.l10 (deleted)

Atitit. view the nature and principles of pre-compiled SQL question marks and view native SQL statements and atititsql   Atitit. view the nature and principles of pre-compiled SQL question marks and view native SQL statements   1. Pre-compilation

Oracle users are locked and oracle users are locked Sqlplus sys/password @ localhost: 1521/cmsx as sysdba   SQL * Plus: Release 11.2.0.1.0 Production on Monday July 21 13:33:13 2014 Copyright (c) 1982,201 0, Oracle. All rights

Mutex (test), mutexHow to Use Mutex for cursor sharing Kks uses mutex to protect a series of operations based on parent cursor parent and child cursor For the parent cursor operation of the parent cursor: Different wait events are generated based

Access denied for user: 'root @ localhost' (Using password: YES ), After mysql is successfully installed in centos First use of root logon: Access denied for user: 'root @ localhost' (Using password: YES) The reason is that the root password in