Database Administrator

PrefaceEvery DBA in the Process of database management should inevitably encounter a variety of errors (ORA-1547, ORA-904, ORA-1578 ......). Some errors are often called "classic errors" by Oracle DBAs due to frequent and complex causes ". The ORA-31

-- System permission listSelect * from dba_sys_privs p where p. privilege like '% LINK %' -- Object permission tableSelect * from dba_tab_privs tp where tp. owner = 'Scott' -- What I see on the Internet:--- ALL_COL_PRIVS indicates column

Move the Oracle database audit-related tables to other tablespaces: Because audit-related tables such as AUD $ are stored in the SYSTEM tablespace, it is best to move AUD $ to other tablespaces to protect the SYSTEM tablespace without affecting

Environment: RHEL-5.8 Oracle _ 10gR2 Bind a bare Device [Root @ localhost ~] # Fdisk-l Disk/dev/sda: 32.2 GB, 32212254720 bytes 255 heads, 63 sectors/track, 3916 cylinders Units = cylinders of 16065*512 = 8225280 bytes Device Boot Start

1. Use zabbix + Shell scripts to monitor Mysql master-slave replication. An alarm is triggered when an exception occurs in the slave database. 1.1 first authorize a monitoring account to mysql slave. 1.2 compile a script to monitor the slave

Move the MySQL database directory on Linux today The configuration is as follows: /Etc/my. cnf [Mysqld]Datadir =/home/mysqlSocket =/var/lib/mysql. sock The following problems occur when the configuration file is changed and MYSQL is restarted: 110222

When viewing Apache log, the url is often mixed with characters such as % 3A and % 2F. What exactly does it represent? You only need to use Oracle built-in Function Conversion. Query characters in hexadecimal notation: Select chr (to_number ('2f ',

MySQL database backup tool has its own mysqldump, which is an official mysql backup tool. However, mydumper, a third-party backup tool, is advantageous for more people. Next we will test and verify the backup efficiency between them. 1. Install the

Recently, after Oracle Developer Suite has been installed, you cannot log on to the system, enter an account logon error: ORA-12154: TNS: failed to parse the specified connection identifier. Generally, this is because the configuration file does

Differences between primary keys, indexes, and pages of Oracle and MySQL: 1. Primary keys. Oracle cannot implement auto-increment, and mysql can implement auto-increment. Oracle new sequence, SEQ_USER_Id.nextval 2. Index: Mysql index starts from

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

For DBAs, the most basic task is to back up and restore the database. In case of exceptions (such as server downtime or disk damage), the data department should be lost, or, the loss is minimized. MySQl database provides many tools (such as

For example, in the employee basic information table, there are employee names, employee positions, birth dates, and so on. If the three fields in the current view are displayed in the same field, there is a delimiter in the middle. For example, I

OCILIB is a cross-platform Oracle driver that provides fast and reliable access to Oracle databases. It provides a rich, fully functional, and easy-to-use API. OCILIB supports all running Oracle platforms. # Include "ocilib. h" Int main (int argc,

The following issues suddenly occurred when logging on to Oracle:ORA-00257: archiver error. Connect internal only, until freed. If you are confused, it may be caused by insufficient space for archiving logs.Log On As A sysdba User:Query the space

Oracle has set a good reference for us, that is, the scott user and the employee table. Today, we will start with the emp table to study the group usage.  SQL> select * from emp2; EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO--------------------------

1. Install MySQL database You can install MySQL in CentOS5.4 in either of the following ways:1. Install MySQL based on the source code package (I .e. the tar package;2. MySQL installation Based on RPM packages; The following describes how to install

I accidentally read the following figure: This is the structure of a scores table, which has two faminly: course, grade   Next let's take a look at the regrioninfo information: 2147483647 BLOCKCACHE 2147483647 BLOCKCACHE REGION => {NAME => '

Delete the Oracle database first ~~ SQL> shutdown immediate; SQL> startup mount; SQL> alter system enable restricted session; SQL> drop database; Start manual Oracle database creation Vi. bash_profile Source. bash_profile (it is second in

In the previous article (), after installing postgresql with yum, you can manage it through service. This postgresql-9.1 is located /Etc/rc. d/init. d/postgresql-9.1 You can see that it uses an OS username named postgres by default (from this script,