Database Administrator

There are two types of SQL databases: one is the traditional data table format and the other is the data table format that supports transaction processing (InnoDB, BDB, with InnoDB as the main one ), the following describes how to install and use

1. Install MySQL in Linux The rpm file is a software installation package developed by Red Hat. rpm frees Linux from complicated procedures when installing software packages. The frequently used parameter of this command during installation is-ivh,

I thought that in Linux, ODBC data sources should be created in the same way as in windows. In fact, it is not necessary at all. You can directly connect to Oracle using the JAVA JDBC driver. Use the following statement to load the JDBC driver of

Troubleshooting ORA-01090: shutdown in progress,ORA-01081 Phenomenon:SQL> shutdown immediateORA-01090: shutdown in progress-connection is not permittedSQL> startupORA-01081: cannot start already-running Oracle-shut it down firstSolution:Oracle>

I have previously introduced the usage of SELECT... FOR UPDATE, but the locking data is a distinction. Because InnoDB defaults to Row-Level Lock, MySQL will only execute Row lock (only Lock the selected data example) If a specified Primary Key is

1. An error occurred while installing the Mysql *. rpm package. Error: Failed dependencies:Perl (CGI) is needed by MySQL-client-4.0.26-0Perl (DBI) is needed by MySQL-client-4.0.26-0Error: Failed dependencies:Perl (DBI) is needed by MySQL-server-4.0.2

It took a week for the project team to configure RAC. Because I had no experience before, I had a lot of detours in the middle. It was also done by making great efforts on GOOGLE. It's not easy to think about it. Now we have to record the problems

To install MySQL In Debian, follow these steps: Debian:/# apt-get install mysql-server After installation, the root account has no password by default and can be changed. Debian:/# mysqladmin-u root password $ (yourpass) You can modify some

The absence of an index on a foreign key column can cause two problems: Limiting concurrency and affecting performance. Either of these two problems may cause serious performance problems. Both the official Oracle documents and Tom's books indicate

Preface The Master-Slave database mechanism solves many problems, especially for applications with high read/write performance. 1. All write operations are performed on the Master node, and the Slave database node regularly reads the bin-log of

In Linux, view the MySQL storage engine: Server version: 5.0.45 Source distributionMysql> show engines;+ ------------ + --------- + ---------------------------------------------------------------- +| Engine | Support | Comment |+ ------------ + -----

Differences between stored procedures and functions in Oracle 1. You can use the out parameter to return multiple values. Generally, multiple return values are used. If only one return value exists, use the function. 2. The process call itself is a

When using MySQL, we often encounter table names that do not comply with the specifications or standards, but there is already a large amount of data in the table. How can we keep the data and only change the table name? You can create a table with

Oracle has three table connection technologies: Nested connection, merge connection, and hash connection. 1. nested loop Join) Nested connection divides the dataset to be processed into an External Loop (driving data source) and an internal loop

AsmcmdConnected to an idle instance.Sh:/Oracle/db/product/11g/bin/clsecho: No such file or directory This error is caused by an incorrect environment variable, because I did not create a grid account when installing the grid and directly installed

This article introduces how to install two versions of Oracle Database (oracle 10g/11g) on a host. The system environment uses ol5.8 and uses oracle-validate-rpm to automatically configure the oracle system environment. The installation path needs

Use the built-in functions of mysql: INET_ATON (expr)Given the dotted-quad representation of a network address as a string, returns an integer that represents the numeric value of the address. Addresses may be 4-or 8-byte addresses.Mysql> SELECT

One day early morning, I received a db Fault Warning and went to the machine for check. mysql was restarted by the myqld daemon. Check/var/log/messages and the recent dmesg and find that the mysql process is killed by oom. The following is an

Common Data Backup Types and toolsMysqldump Backup ToolUse LVM logical volume Snapshot Backup#####################################Common Data Backup Types and tools I won't say much about the importance of data ......, Common Data Backup types are

1. Preface Recently, I have been studying MongoDB. I have learned a lot about data modification and complicated commands. So I will summarize some frequently used modification commands in this blog to facilitate future study. 2. Command Summary 1).