Database Administrator

1. Are you familiar with databases SQL2005 and Oracle? SQL2005 is a database product of Microsoft. It is an RDBMS database, which is generally used in some medium-sized databases and cannot be used across platforms. ORACLE is a data product of

When creating a new user, you must specify the default tablespace; otherwise, the system tablespace will be treated as the default tablespace. This is not recommended. It is estimated that the default tablespace was not specified when a user was

MySQL version 5.1.49 # Uname-Linux loDB192168000046 2.6.18-238.19.1.el5 #1 SMP Fri Jul 15 07:31:24 EDT 2011 x86_64 x86_64 x86_64 GNU/Linux # Cat/etc/issueCentOS release 5.6 (Final)Kernel \ r on an \ m # Mysqlhotcopy-u root-p 'Password' database name

SQLite statement: Select count (*) FROM sqlite_master where type = 'table' and name = 'student '; If yes, 1 is returned; If it does not exist, the return value is 0. C # statement: SQLiteCommand mDbCmd = mDbConn. CreateCommand (); MDbCmd.

Recently, an error occurred in the Oracle database data file of a customer, resulting in a failure to start.After recovery, the data file status is normal and the database seems to be open.(Note that the database status is normal. This does not mean

Definition: Row migration: Because of update, the rows become longer, the original blocks cannot be placed, the rows are moved into the new blocks, Line link: The line is too large at the beginning. For example, if you insert a row of bytes, you

Version: OS: Enterprise Linux Server release 5.7 Db: Release 10.2.0.1.0 Ogg: Version 11.2.1.0.1 Prepare beforehand (both nodes must be prepared ): 1. Install and start Oracle, upload ogg installation media to/ogg, and decompress 2. Create a ggusr

The solution is to use the hstore type. to use it, you must first create the corresponding extension. The following is a simple example: Iihero = # create extension hstore;CREATE EXTENSIONIihero = #Iihero = # select 'a => 1, B => 2': hstore;Hstore-

Environment: SQL> select * from v $ version where rownum = 1; BANNER ---------------------------------------------------------------- Oracle Database 10g Enterprise Edition Release 10.2.0.1.0-Prod SQL>! Uname-r 2.6.18-308. el5xen The

I. Summary of list Common commands THE list command lists the backup information in the control file and RMAN recovery directory, which is one of the most intuitive ways to understand all visible database backup files. List incarnation; List backup

Oracle dynamic SQL statements are easy to use, but the assembly process is too annoying. Especially when a date field is involved in the Assembly Statement, to_char must be added during the Assembly to convert it into a character first. In SQL,

Recently deployed project, the following message is displayed in the Linux system for testing (such as test) tnsping orcl using non-Oracle users: TNS Ping Utility for Linux: Version 11.2.0.1.0-Production on 04-DEC-2012 14:29:28 Copyright (c) 1997,200

Preface After installing MySQL, you must optimize and adjust various MySQL Parameter options. Although the MySQL system is highly scalable, it can run efficiently in an environment with sufficient hardware resources or in a few resource environments.

There are three types of pages for Oralce. 1. rownum Select * from emp 2. Display rownum [allocated by Oracle] Select a1. *, rownum rn from (select * from emp) a1; 3. Several query changes A. to specify a query column, you only need to modify the

1. The binlog logs are deleted several more times and the MySQL master is not synchronized. Mysql> show slave status \ G; Slave_IO_Running: NoSlave_ SQL _Running: Yes View the error log [ERROR] Slave I/O: Got fatal error 1236 from master when

On the Red Hat Enterprise Linux platform, the MySQL master-slave synchronization principle is used to achieve two-way MySQL synchronization.MySQL version: 5.5.28Operating System: RHEL 5.8 32bitServer1: 192.168.1.1Configuration: my. cnf Server-id =

In the last week, I reviewed index-related things. In addition to reviewing concept, I also saw a good document on MOS. Share with you. Document No.: [ID 30405.1] This article is only concerned with B * tree indexes which are currently the most

The current environment is a dual-node RAC with the version of Oracle 10.2.0.5. The hostname is racnode1, and racnode2 needs to add a new node racnode3. The OS version is Oracle Linux 5.7 x86_64 Ensure normal operation of RAC Configure public IP,

Oracle uses the spfile . ora file as the startup parameter file. If the file does not exist, search for the spfile. ora file. If the spfile . ora and spfile. ora files do not exist The init . ora file is used. If none of the preceding three files

Q: How to back up data under a field in a table in the Oracle database? This problem has plagued me and found a lot of information about it through Baidu search. But none of them can help me solve this problem. Solution: try to create a temporary