Database Administrator

Transactions are also an important aspect of access to the persistence layer of Hibernate. Hibernate not only provides support for local transactions, but also allows the use of container-managed global transactions. Hibernate has the following

1. Install MongoDB Mongodb home http://www.mongodb.org/ 1, download the required version, address: http://www.mongodb.org/display/DOCS/Downloads (Take windows as an example, linux should be relatively simple), can refer to the official document:

The Oracle storage outline is used to provide stable execution plans. Starting from oracle 11g, it is gradually replaced by the SQL plan. The following describes the specific process of the storage outline. The results are tested in oracle 11g r2.--

Scenario 1:[Oracle @ www.bkjia.com ~] $ Sqlplus/as sysdbaSQL * Plus: Release 11.2.0.1.0 Production on Tue Jun 26 20:52:47 2012Copyright (c) 1982,200 9, Oracle. All rights reserved. Connected:Oracle Database 11g Enterprise Edition Release

An error message is generated in alert. log during manual RMAN backup on Sunday.Sat Jun 25 16:39:08 2012Errors in file/home/Oracle/app/oracle/admin/XXX/udump/XXX_ora_22899.trc:Sat Jun 25 16:39:08 2012Errors in

MySQL does not support directly writing SQL statements to implement the Circular insert function. You can use other languages to manipulate MySql or use stored procedures to implement this function. 1. Implementation of Stored ProceduresA. Create

DRCP is the Database Resident Connection Pool. The default Database is sys_default_connection_pool, but it is not opened. Start DRCP:Sqlplus/as sysdbaExecute dbms_connection_pool.start_pool ();It can be executed on any instance in the RAC

Manually add control filesMethod 1,1. Modify the control file information in the parameter file spfile.SQL> alter system set control_files ='/Database/oradata/yang/control01.ctl ','/Database/oradata/yang/control02.ctl

1. When a table is created, double quotation marks are added. The case sensitivity of the table name will be retained and written to the database, Note: Double quotation marks are not written into the database, and Oracle converts them to uppercase

Recently I encountered the problem of "TNS-12535: TNS: Operation timeout. 1. First, check whether the server has enabled the firewall. The firewall blocks connections.Linux Firewall shutdown command: service iptables stop or chkconfig iptables off2.

First, check the machine environment and check whether there are any residual database installation directories and related users. If they are found, they will be deleted.Check whether the/opt/IBM directory contains db2 files.Next, let's look at the

1. view the maximum number of Oracle connectionsSQL> show parameter processes # maximum number of connections 2. Modify the maximum number of connectionsSQL> alter system set processes = value scope = spfile # value indicates the number of

DRBD (Distributed Replocated Blocak Device) Distributed replication block DeviceIn Versions later than 2.6.33, DRBD is compiled into the kernel, so DRBD works in the kernel. Let's take a look at the workflow of DRBD: 650) this. width = 650; "> When

1. Introduction Use synonyms to access the same object: (1) convenient access to other user objects (2) Shorten the Object Name Length 2. Create a synonym SQL> create synonym syn_emp for scott. emp; You have created a synonym. 3. Delete

Establish package specifications Create Or ReplacePackage emp_packageIs G_deptno number (3): = 30; ProcedureAdd_employee (eno number, ename varchar2, sal number, dno numberDefaultG_deptno ); ProcedureFire_employee (eno number );

Oracle job is a function provided by oracle to regularly execute a stored procedure or package. Main scenariosPerform related operations on the background at regular intervals. For example, save the data of one table to another at every night, and 2.

Test Oracle 11g fixed execution plan-Baseline 1. Select SQL _id SQL>Pagesize 300 SQL>Set linesize 300 SQL>Set autotrace on SQL>Var name varchar2 (10 ); SQL>Exec: name:='It'; Select department_name From hr. departments dept Where

In many cases, some slow queries cause a lot of pressure on MongoDB. It took some time to write a script and kill some slow query operations. Var j = 0; Var _ DEF_TIME = 10;// Set the slow query time For(Var I in db. currentOP ().

Architecture and Backup recovery principles1. The most important thing about Oracle database is online redo log.AnalogyControlfile: corporate executivesDatafile: Production WorkshopOnline redo log: Finance DepartmentNote:System tablespace is the

Oracle logminer is a tool used to analyze archived logs. Here I will list a simple and efficient use process. 1. initialize parameter configuration Alter system set utl_file_dir = '*' scope = both; This requires a restart to take effect. SQL> show