Database Administrator

When I reinstall the MySQL service today, the following error occurs: C: \ Program Files \ MySQL Server 4.1 \ bin> MySQLd-nt -- removeService successfully removed. C: \ Program Files \ MySQL Server 4.1 \ bin> MySQLd-nt -- installService successfully

 I recently encountered this problem and found that the connection saved in the MySQL database connection pool has expired. The following is an official explanation. From MySQL 5. after a version of x, the feature of MySQL to automatically close

The source code of mysql. the serial number is mysql-5.0.20a.tar.gz. Of course, the other code can be used only for testing. Red Hat Linux as 4 is used for Linux. Installation steps: 1.decompress mysql-5.0.20a.tar.gz. Command: tar-zxvf Mysql-5.0.20a.

The installation of Oracle-xe in Ubuntu 8.04 for the first time was quite smooth. Only the error "/etc/sysconfig/oracle-xe" does not exist at the end, but it can be used. You can also enter the WEB management interface. I downloaded the deb package

After the archived logs are manually deleted, the Rman backup detects that the logs are missing and cannot be further executed. Therefore, you need to manually execute the crosscheck process, and then the Rman backup can be restored to normal. 1.

1. Export the entire database Mysqldump-u username-p Database Name> exported file name Mysqldump-u wcnc-p smgp_rj_wcnc> wcnc. SQL 2. Export a table Mysqldump-u user name-p database name Table Name> exported file name Mysqldump-u wcnc-p smgp_rj_wcnc

Non-RAC Environment Character Set Modification 1.1 Oracle Character Set Problem Summary 1.1.1 concept of oracle Character Set The oracle character set is a collection of symbols for the interpretation of byte data. It can be divided into different

In some cases, if only one query result is known, using LIMIT 1 in SQL statements will increase the query efficiency. For example, the following User table (primary key id, email address, and password ): Create table t_user (Id int primary key

As part of the performance comparison between MySQL 5.5 and 5.6, I have studied the differences between the default parameters of the next two versions. To understand the differences, I used the following SQL statements to query MySQL 5.5 and 5.6

You can create and delete indexes in two ways: alter table and create/drop index. alter table:Alter table tbl_name| ADD {INDEX | KEY} {INDEX_NAME}{INDEX_TYPE} (INDEX_COL_NAME,...) [INDEX_OPTION] ......| DROP {INDEX | KEY} INDEX_NAME Alter table

Every day, Internet companies collect log files to find desired information, such as the installation volume and activity of a software. All the information must be stored and displayed. The following describes the implementation process. The

Most of the steps to use hive for data analysis are to use hive to export the statistical results to a local file or other Hive tables, import the local file to mysql or use sqoop to import the Hive table to mysql. Today, my colleague recommended a

When a request was submitted today, the ORA-01652 was prompted that the TEMP segment could not be extended through 128 (in tablespace temp. Finally, use alter database tempfile '/*/db/apps_st/data/tempx01.dbf' to RESIZE 7168 M; to expand the

This section briefly introduces flashback database, which can be executed in RMAN or SQL * PLUS. Sometimes it is quite practical. Prerequisites: 1: The Archive mode is required. 2: The flash recovery area must be specified. SQL> show parameter

How to disable and start Oracle 10g RAC Scenario 1: maintain the database and operating system, servers, and shut down the database (all instances), OS, and Server. A. Stop the Oracle10g environment first$ Lsnrctl stop (you can also use srvctl to

UPDATE queries are tricky because you cannot simply write multiple values. In different situations, I use different solutions. If you are sure that the record to be updated exists, you can use INSERT... on duplicate key update instead (Leave a

The master-slave replication procedure for MySQL is very simple. You must understand it carefully. Environment: A: 192.168.1.1 as the master with no data B: 192.168.1.2 as slave, no data I. On the master server: Note: mysql Parameters Binlog-do-db =

OracleOraDb10g_home1TNSListener:This Service corresponds to % Oracle_Hoem \ bin \ TNSLSNR. EXEIf the service is not started, Oracle errors will occur-Ora-12514: TNS: no listeners. OracleServiceORACLE:If the service is not started, it will cause

The B + tree is a classic data structure generated by the combination of the Balance Tree and the binary search tree. It is a balanced search tree designed for disks or other direct access devices, in the B + tree, all record nodes store the key

The client software cannot connect to the server. The following error message is sent when you view the database log information: Tue Jun 25 25 12:02:52 CST 2013 Errors in file/home/Oracle/orabase/admin/ORACLE/bdump/oracle_q000_3529.trc: ORA-00600: