Database Administrator

Because it is mainly used to manage the database platform, it has had a lot of dealings with the relevant technical staff of various departments of the company. Then, I learned a lot about the concept of the database from the daily communication, if

When a Cassandra cluster needs to be invested, initialization data is usually used, for example, all the blog data on a blog website, all the webpage information on a data analysis website, and all the product information on an e-commerce website.

"Memory is a new hard disk, and hard disk is a new tape" is from the Turing prize winner Jim Gray. I. Preface I understand that random I/O should be put into the memory, and the sequential I/O like the tape should be left to the hard disk, excluding

The execution plan is simply the result calculated by the query optimizer, which indicates the most efficient way to execute the submitted query. The execution plan tells you how the query is executed, so it is the basic means for DBA to diagnose

Oracle 9i is newly installed today. After Tomcat is started, the relevant oracle page is displayed at http: // localhost: 8080, management tools-Shut down the http service of oracle in the service and start tomcat again. It seems that there is a

Recently, Sybase, an enterprise architecture and mobile software provider, has released its fourth-generation advanced programming language, 4GL, Fast Application Development (RAD) tool Sybase PowerBuilder 11. With its advantages in rapid

Blog from zsf8510: 1. -- secure The IP number returned by the gethostbyname () system call is checked to ensure that they are resolved back to the original host name. This makes it harder for some outsiders to obtain access permissions by imitating

INSERT new data using the INSERT statement Syntax: INSERT [INTO] tbl_name [(col_name,...)] VALUES (pression ,...),...INSERT [INTO] tbl_name SET col_name = expression ,... Let's start to use the INSERT statement to add records. This is an SQL

I. Shared pool tunning The Optimization of the Shared pool should be given priority, because a cache miss occurs in the shared pool, which is more costly than the data buffer, because the dictionary data is generally longer than the data stored in

Isolated user problems For example, many tables in the previous database were created by user test. However, after we restored the database, the user test became an isolated user and did not have the corresponding login username, even if you have

Introduction The DB2 agent is a process or thread located on the DB2 server that serves application requests. When an external application connects to a DB2 instance to request access, the DB2 proxy is activated to respond to these requests.

Database administrators must always pay close attention to potential database problems that may negatively affect the availability or performance of each system they manage. Generally, the database administrator can monitor and maintain the system

Many people think it is not very difficult to allocate permissions for Oracle users. However, you need to be careful and patient in assigning permissions for Oracle users. This article will talk about how to assign to mid users. Authorize all the

Let's talk about database issues. I have seen several statements on the Internet. Let's take a look at whether they are correct or not, and whether they are ambiguous or misleading. 1. or may cause a full table scan. 2. in may cause a full table

I have been thinking about the following question recently:How to Create a performance model for a database? As a DBA, we are faced with a huge challenge: how to ensure that the database performance can meet the needs of rapidly changing

If you have a one-to-many relationship and want to Join two tables, but you only want to generate a row in each "one-to-many" relationship, you can refer to the following: A simple example is as follows: If you want to obtain the essay ID, Title,

Introduction: Remote database managementAs one of the hottest trends in the database market, remote database management is a service provided by a third-party company-within the scope of compliance with established rules, A third-party company

There are a lot of articles on Database optimization, but some of them seem to be incorrect and some are impractical. For a single database, they can only be better, not the most optimal, and because of different actual needs, there are still some

Modify an earlier project today. After running the project and select a query page, the system prompts "constraints cannot be enabled. One or more rows contain values that violate non-null, unique, or foreign key constraints ." . Cause analysis:

Single Replication sets design: , 10.9.3.228, only Mongos and config services are started. ^_^[root@:/usr/local/mongodb/bin]#cat runServerConfig.sh   ./mongod --configsvr --dbpath=../data/config --logpath=../data/config.log --fork