Database Administrator

1. Open flashback: Close Database SQL> shutdown immediate; Mount Mode SQL> startup mount; If the archive is not enabled, open archive [because flashback depends on Media recovery, archive must be enabled before flashback is enabled] SQL>

Here we will mention two possible problems. FirstBatch Processing TaskThis task may not have enough space to complete the Redo, or because the speed is fast, the online redo log has been switched before it is archived to the offline redo log (all

Comparison Statement of Oracle Database Object growth record query: Select * from (Select a. owner, a. segment_name, a. tablespace_name, B. megas-a.megas diffFrom(Select owner, segment_name, tablespace_name, sum (megas) megasFrom object_rdWhere

After installing a new device, due to operation errors in the parameter value added more than 0, resulting in SGA_MAX_SIZE and SGA_TARGET set the value is too large, when restarting the database prompt ORA-27100: shared memory realm already exists.

This type of requirement is usually met in JAVA development. If a piece of data already exists in the table, update it. If it does not exist, insert new data. If you do not use the merge syntax provided by Oracle, you may first need to query the

In daily workDBAData transfer is often encountered. The most typical thing is to import the database running in the online system to the test environment for related upgrade tests and stress tests. The following two methods are used to clone a

1. Import CSV data The content of the user.csv file is as follows: _ Id, name, ageObjectID (4eed9f9ca939118694cf05e4), "ming", 10ObjectID (4ef1f3cf3bd18218e6bdfa31), "lisi", 20   You can import the data in user.csv to the user set of the localdb

Em for configuring non-default listening PORT (1521) (※parameter name-SID and-PORT must be in uppercase)Emca-config dbcontrol db-repos recreate-SID t11g-PORT 1715Dynamic listening must be configured:(You need to manually register listener for

C: \ Oracle \ product \ 10.2.0 \ client_1 \ BIN> rman target sys/password @ DGP  Recovery MANAGER: Release 10.2.0.1.0-Production on Tuesday January 31 00:59:06 2012 Copyright (c) 1982,200 5, Oracle. All rights reserved. Connect to the target

1. Create a test table and data first,CREATE TABLE EMPSelect level EMPL_ID,(MOD (ROWNUM, 20) + 1) DEPT_ID,SUBSTR (DBMS_RANDOM.STRING ('x', DBMS_RANDOM.VALUE (20, 50), 0, 10) EMPNAME,TRUNC (DBMS_RANDOM.VALUE (1000,500 000), 2) SALARY,DECODE (ROUND

1. Row-Level Lock:(The following statement adds a lock to all rows in the table)Select * from person for update; If this row of record is locked, the system directly throws an error ora-00054 without waitingSelect * from person where id = '1' for

Environment: RHEL6 + MySQL-server-5.5.18-1.el6.i686 + MySQL-client-5.5.18-1.el6.i686 Problem: Directly download the package and use RPM for installation. An error is displayed. Run rpm = pa | grep mysql * to check whether MYSQL has been installed.

Oracle redo online Log File reconstruction in seven steps redo online log reconstruction in five minutes redo log Reconstruction Step 1: create three new online log groups: ALTER DATABASE ADDLOGFILEGROUP4

MySQL description: An article library contains two tables: category and article. There are 10 classified data entries in category. There are 0.2 million articles in articles. In article, there is a "article_category" field that corresponds to the

1. Disable the startup of related CRS resources and stop these resources (vip, listener, scan, scan_listener, database) 1.1 disable database startup and stop on all nodes [Grid @ rac1 ~] $ Srvctl disable database-d racdb [Grid @ rac1 ~] $ Srvctl

How to allow remote MySQL user access (successful test in Ubuntu) 1. Log On with the root user and perform the following two steps (Note: [password] indicates the actual password of your root user ): 1.1 use mysql; 1.2 grant all on *. * TO 'root'

Overview of RAC archive log sharing Whether the database is single-node or cluster, the way it carries things is strictly in the order of timestamps. This determines that the log records should be read in strict chronological order during database

Step 1: Download and decompress the sqlite source code package > Wget http://www.sqlite.org/sqlite-3.6.16.tar.gz > Tar-zxvf sqlite-3.6.16.tar.gz Step 2: Install >./Configure-disable-tcl > Make > Make install Step 3: write code for testing > Vim

Oracle learning Dynamic Performance Table v $ locked_object This view lists all the locks obtained by each transaction on the system. Description of columns in V $ LOCKED_OBJECT: XIDUSN: rollback segment numberXIDSLOT: Slot NumberXIDSQN: serial

In Linux, use mysqldump to regularly back up MySQL databases: #! /Bin/bash PATH =/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin :~ /Bin Export PATH Export LANG = en_US.UTF-8 Savedir =/log/database_bak/ Cd"$ Savedir" Time ="$