Database Administrator

When MySQL cursor is used, the last row is read repeatedly. Later, we found that we should put the read data in the next loop to avoid duplication. The Code is as follows:DELIMITER $ USE 'test' $ Drop procedure if exists 'SP _ getalltablename'

This chapter describes the logical Storage Structure and relationships of Oracle databases, including the following:1. Introduction to data block, extent, and segmentIi. Data Block overviewIii. Overview of ExtentIv. Segment OverviewI.

After switching to Oracle11g today, when UTL_TCP was used to interact with the Service Program, an ACL Access Control Problem was reported. Fortunately, there were still some network basics, what is ACL, In the Oracle11g environment, to enhance the

After installing Oracle in the notebook, you can use the OEM console normally. However, after logging out, log on again or restart the system, or change the network environment of the notebook, problems may occur. The solutions to these problems

Background: Recently, I encountered a very BT project where I used the image disk array of the database for RMAN backup. Archive logs generated in the production environment need to be cleared regularly. In addition, because the image disk array is

I. Exceptions: During database operations during development, the field encounters big data and the field is not BLOB. When the CLOB type is used, if the PreparedStatement method is used to setString, the following exception occurs: java. SQL.

The bare device created in AIX is the logical volume in AIX. The creation method is as follows: Syntax: mklv-t raw-y [lvname] [vgname] [LPs] For example, when creating a bare device required by Oracle: Mklv-t raw-y lv_sysaux datavg 3 Mklv-t raw-y lv_

When you use ROLLUP or CUBE for GROUP operations, fields with NULL values are generated, then, how can we tell whether the field itself is NULL or generated by ROLLUP and CUBE? In this case, GROUPING (groupingfield) can be used to solve the problem.

I. Overview of software and hardware Environments Two redhet Enterprise-R4-U4 systems rac1 and rac2 are installed on the Virtual Machine VMware GSX Server, and the Oracle10g RAC environment is built on the virtual shared storage. 1. rac1 two NICs:

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,

By default, MongoDB does not need to enter the User and password, so the client can log on. This security problem is serious. There are also many examples on the Internet, but there are also many details that many people have not noticed me here by

The principle is just a concept, and the operability is not strong. I read N-plus semi-Principles and semi-Details related articles, but I am always confused by various details. In order to quickly use PostgreSQLProcedure for configuring a

Data File recoveryRestore accidentally lost data files after being closed in the open stateBesidesSystem tablespace data file (mount)Besides,Other data files can be restored in the open (mount) state.. Restoring data files in the open state can

Connect:Oracle Database 11g Enterprise Edition Release 11.2.0.1.0-ProductionWith the Partitioning, OLAP, Data Mining and Real Application Testing options SQL> show parameter sec_case_sensitive_logon NAME TYPE VALUE------------------------------------

Most of the time, the operating system is Windows, and Liunx is rarely understood.During this time, an image system requires that all applications be deployed on the RedHat system. In this way, there are two software usage problems: 1. Database 2.

MysqlExecution Process: MysqlIt is a single-process service, and every request is responded by a thread. This requires a connector to handle new user requests, responses, and destruction. 1.Client request, server (connector) opens thread to respond

Last week, a colleague encountered an error while installing Oracle in Linux. The installation was not successful. The supervisor asked me to re-install it. Only after all the previous installations are deleted can we ensure the installation is

Basic Linux operations Uname-r view kernel version Df-m to view the space of each storage device Du-sh: view the current directory space size View processes and IO: top, mpstat-p all 1 100, iostat-x 1 10 (test IO performance) Force Delete the rm-rf

First, log on as an Oracle user 1. $/oracle/app/product/101/bin/dbstart: Start the database. 2. $/oracle/app/product/101/bin/dbshut: Shut down the database. 3. $/oracle/app/product/101/bin/dbca: Database Configuration assistant for database

The Oracle version in this document is 11.2.0.1. No OEM was installed before. An error is reported when dbca is used for installation today. The error page is as follows: I have previously reviewed an OEM reconstruction method: Oracle OEM