Database Administrator

Database Backup is an important means to ensure database security. Most database administrators have discovered the importance of backing up databases, and even have great dependence on them. Therefore, the database administrator must ensure that

This is the first time I have installed MySQL on Ubuntu Linux 9.04. I have not installed MySQL before. So I have made some configurations by referring to some network articles. The following is the entire installation process. I. Installation and

Deleting a database table from Oracle 10 Gb does not actually Delete the table, but stores the table in recyclebin. This process is similar to that of deleting files in windows and is temporarily stored in the recycle bin. The system automatically

Preface:It is not difficult to specify a data type for a column. It is difficult to specify a suitable data type. For the same string type, choose a fixed length or a variable length, among which there are many articles. Therefore, you need to

MySQL multi-thread logical backup About MydumperMydumper is a multi-threaded MySQL logical backup tool. Fast logical backup (compared with mysqldump) Consistent backup of myisam and innodb tables If the myisam table is not used, there

In MySQL, there are actually two filesort implementation algorithms. One is to first retrieve the corresponding sorting fields based on the corresponding conditions and the row pointer information that can be directly located in the row data, then

1. First set Oracle_SID = manual2. Create a password fileGo to the/u01/app/oracle/product/10.2.0/db_1/dbs directory and run the command to create the Database Password File.[Oracle @ myorcl dbs] $ orapwd file = orapmanual password = oracle3. create

(I) First query the CPU and IO usage at the system level: top, iostat, sar... (Ii) EXEC DBMS_WORKLOAD_REPOSITORY.CREATE_SNAPSHOT (); (Iii) rman target/debug trace =/tmp/rmandebug.txt log =/tmp/rman_log20130727.txt Execute backup (Iv) EXEC

1. DBA_LOGSTDBY_EVENTSThis view can be viewed as a logical Standby operation log. If an error occurs, you can view the recent logical Standby operations in this view. By default, this view retains only the records of the last 100 events (you can

ORA-01017 When connecting to the database, I don't know if the original server-side program didn't stop, so I encountered a few problems with database connection. It was a bit strange. Later, I re-opened the project and compiled it again. When

For physically damaged data blocks, we can use the block media recovery function of rman block media to restore the damaged blocks, instead of restoring the entire database or all files to fix these small amounts of damaged data blocks. Restoring

Solution: (1) Track and execute the inserted SQL/stored procedure, find the row that causes the culprit, and insert the row again after modification. (2) The simplest way is to increase the precision of the target field.   Because the specific table

Physical Data Guard role conversion steps   Step 1 verify whether the role of the master database can be converted to the slave database (the original master database)   SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE;SWITCHOVER_STATUS ---------------

ORA-16139: media recovery required error encountered during physical DG Master/Slave database switchover SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY; ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY * ERROR at line 1: ORA-16139: media

When I use Navicat to connect to a remote MySQL instance, the following error is displayed. I thought it was a firewall problem, but it was disabled. I think this English paragraph is a bit misleading, and it is a problem on my own side. Check the

Tutorial start:1. Install MySQL Note: perform the following operations on the two MySQL servers 192.168.21.169 and 192.168.21.168 respectively to install MySQL 5.5.22. 2. Configure the MySQL master server (192.168.21.169)Mysql-uroot-p # enter the

Background: I was asked this question before the interview. There are two transactions in the database. When transaction1 is updating a row, Will transaction2 block during select. I used MySQL for tests before, but I was impressed. But the

A buddy raised a question and found it interesting. He studied it below:The Development Department of this buddy company has written a jboss script to start the jboss program. You need to enter a command similar to the following:./Jboss_init.sh

I recently used LogMiner to mine logs on Oracle 10 Gb. I did not intend to create table test as select * from v $ logmnr_contents. I found that there are actually records, but the recorded content cannot be parsed, the info field reports In Memory

These three table join methods are the most basic connection methods for Oracle:Hash join PrinciplePrinciple of sortmerge join Nested loop join) Number of visits: the number of times the driver table returns and the number of times it is accessed by