Database Administrator

Latch indicates the locking mechanism that occurs when processing data between running processes of the Oracle database. Lock, which indicates the differential locking mechanism when concurrency occurs between specific objects in the oracle

I have just studied Linux and are still studying OCI. After calling OCI to connect to the database a few days ago, I tested it with the example provided by Oracle. I can read data normally (in English), so I can rest assured that I can switch to

I. How to completely delete the old version of Oracle 1. Run DBCA in cmd and delete the Oracle instance here;2. Find the Universal Installer under the Oracle subdirectory in the Start \ Program and run it to uninstall the Oracle software;3. Go to

Speaking of this problem, I am very ashamed. It was in my previous article "Configuring IP address () in Ubuntu7.10" that solved step 2's problem, this causes the problem that mysql cannot be logged on or cannot be installed again. I apologize to

1. Modify the Oracle system configuration file/etc/oratab/Etc/oratab format: SID: ORACLE_HOME: AUTOSet the AUTO domain to Y (uppercase). Only in this way can dbstart and dbshut of oracle be used. Mine is:Ora9i:/home/oracle/ora/products/9.2.0: Y2.

In the past two days, I have studied the problem of garbled Characters During MySQL upgrade and finally solved the problem that has plagued me for a long time. Here I will record it and the previous articles have been updated. Change the server that

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 following illustration describes how to install PostgreSQL8.3 In Ubuntu. First download postgresql-8.3.3-2-linux.binRoot @ bai-desktop:/home/bai/liuy # lsPostgresql-8.3.3-2-linux.binRoot @ bai-desktop:/home/bai/liuy # chmod u + x postgresql-8.3.3

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

I have been depressed for many days. By default, the database mysql installed in mandriva is faulty. The problem is more than two connections. Let's talk about it now. 1) install mysql: sudo urpmi mysql 2) Run mysql-uroot. [mysql] ERROR 2002 (HY000):

On June 19, March 23, Oracle announced the release of its enterprise package for development tool Eclipse to enhance the access and use capabilities of this free development tool for Oracle Integrated middleware components. It is undoubtedly a good

For DEV and UAT environments, databases must be in archive mode, but do not need to be backed up. Therefore, the constant increase in archive archiving logs results in a large amount of disk space consumption. In this case, you can use a shell

Environment: OEL + Oracle 11.2.0.3 Change the dbstart file under $ ORACLE_HOME/bin [Oracle @ Seven bin] $ vi dbstart Find this paragraph at the frontend # First argument is used to bring up Oracle Net Listener ORACLE_HOME_LISTNER = $1 // Set

View the maximum number of processes in Oracle:SQL> select count (*) from v $ session # Number of connectionsSQL> Select count (*) from v $ session where status = 'active' # number of concurrent connectionsSQL> show parameter processes # maximum

In the previous article "using Sqoop for data exchange between MySQL and DHFS systems", we mentioned that sqoop allows data exchange between RDBMS and HDFS and supports importing data to HBase from mysql, however, direct import from HBase to mysql

1. nvl Function The nvl function converts a null value to an actual value. The data type can be date, number, character, and must match: for example:Nvl (commision, 0) Nvl (hiredate, '01-JAN-87 ') Nvl (job_id, 'no manager ') Nvl (to_char (job_id),

The first thing to note is that a ORA-01555 error is a "secure" error that will not cause data loss or corruption, but will make the query that receives the error Unable to continue, in the daily maintenance of the database, if only one or two

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

Constraints are used to ensure the integrity of database data. In Oracle databases, constraints, triggers, and application code (process, function) can be used to achieve data integrity, because constraints are easy to maintain and have the best

1. Environment Description OS: AIX6.1 Oracle: 11.2.0.3.0 RAC 2. Accidents The host of NODE 2 in the database has a down accident and should have been switched to NODE 1 normally. However, the switchover failed and the system was restarted to solve