Database Administrator

Differences between user, user account, and schema A user isa person who connects to a user account by establishing a session against theinstance and log on with the user account name A schemais a set of objects owned by a user account. User Account

When creating an Oracle database, we use dbca in most cases, which is simple, convenient, and automated; Today, we will try to create a database manually using the command line method. Oracle software version: 10gR2 Operating system version: win

Pay attention to the following points when starting and disabling Oracle RAC: 1. Check shared devicesIi. Automatically Start RAC and check related processesIii. manually start RAC4. Check the crs, ASM, and database logs during startup. 1. Check

Editor's note: expansion of existing systems is a big or small challenge for each technical team. Especially for banking businesses, it is not easy to implement expansion by modifying the architecture or rewriting the system because we need to take

Oracle efficient paging storage process: Create Or ReplacePackage JT_P_pageIs Type type_curIsRefCursor;-- Defines the cursor variable used to return the record set ProcedurePagination (PindexInNumber,-- Index of the number of pages to be

1. If the DDL syntax is correct, implicit commit will occur even if the execution fails: Duzz $ scott @ orcl> create table t1 as select * from dept; Table created. Elapsed: 00:00:00. 03 Duzz $ scott @ orcl> update t1 set loc = 'xx' where deptno = 10;

Xtrabackup is an open-source project of percona to implement the innodb Hot Backup function similar to InnoDB's official Hot Backup tool. It can quickly back up and restore mysql databases. Xtrabackup contains two tools: Xtrabackup is a tool used

There are two main causes:1. There is a large volume of transactions that allow Oracle Undo to automatically expand, resulting in excessive disk space occupation;2. There are large transactions that have not been contracted or are not committed by

MongoDB provides the Replica pairs mode to start the database. After the database is started in this mode, the database automatically negotiates who is the master and who is the slave. Once a database server loses power, the other server

1. Run the TOPAS command in the AIX system. It is found that the cpu in the user is too high, and the Oracle process CPU is relatively high. For example, the highest process pid in Oracle is 1138782, accounting for 27% of the CPU. 2. Identify sid

1. Calculation of the table's occupied space Select S. SEGMENT_NAME, DECODE (SUM (BYTES), NULL, 0, SUM (BYTES)/1024/1024) Mbytes From DBA_SEGMENTS S Where S. SEGMENT_NAME = 'mtl _ MATERIAL_TRANSACTIONS '-- table name And S. SEGMENT_TYPE =

1. symptom The database instance cannot respond to client-initiated requests. 2. Type -Oracle processes are waiting for a resource or event -Oracle Process Spins: Spin refers to a loop in which the code in the Oracle Process is executed. In the v $

Object permission test:In the initial state, neither user2 nor user3 has the object permission of user1.t1.Table t1 exists in user1:Duzz $ user1 @ orcl> select * from t1;C1----------1111Elapsed: 00:00:00. 00User2 cannot query user1.t1:Duzz $ user2 @

It is said that there is no relationship between the Write Program and the sequence of database table fields, but it is only known after the actual project is done. For database users, the field sequence of database tables may be cumbersome, for

1. Overview Oracle introduces Redo log for data recovery Related Oracle processes: redo the log write process (LGWR) Related data dictionaries v $ log, v $ logfile Author permission: sys, system permission 2. View redo log information View redo log

I. Overview Development Environment: PHP 5.3.0 +/Symfony 1.4.4/DoctrineMongoDBODM 1.0.0/MongoDB 1.4.4 Tip: This article requires you to understand the following content: PHP namespace, Symfony framework, MongoDB, and Doctrine ODM (download ODM)For

Oracle's RMAN configuration information is stored in the control file of the target database by default. Of course, you can configure a recovery catalog server to store this information. The following is a comparison between the control file and

We have already installed Ubuntu 11.04. We found that apt-get can only install MySQL 5.1. If you want to use MySQL 5.5, you can only compile it by yourself.The compilation and installation process records are as follows: 1. Go to mysql.com to

Environment Description: This environment consists of two mysql Databases and heartbeat. One ip address is 192.168.10.197, the other is 192.168.10.198, and the other is 192.168.10.200. Note: heartbeat itself cannot automatically switch between

There are two ways to verify Oracle login: 1. Verify and log on to the operating system; 2. Oracle password verification; Control parameters: Sqlnet. ora File SQLNET. AUTHENTICATION_SERVICES = (CNT) SQLNET. AUTHENTICATION_SERVICES = (ALL) You