Database Administrator

Oracle partitioning improves the manageability, performance, and availability of many applications. Through the partition function, you can further segment the table, index, and index organization table to more accurately manage and access these

Before starting the OEM, configure the Oracle management server as follows:1. Open the Enterprise Manager Configuration Assistant2. configure a local Oracle management server3. Then, follow the instructions in sequence.After the configuration, a

Starting remote services with the root user has always been a security taboo, because if the service program encounters problems, remote attackers are very likely to gain full control of the host. MySQL has made minor changes since version 3.23.15.

Operating EnvironmentDell 1, 2850Solaris 10x86 u1Oracle 10g Release 2Bash shellComprehensive knowledgeSolaris 10x86 u1 runs in 64-Bit mode on Dell 2850.Oracle 10g Release 2 is a 64-bit architectureReferencesHelp document in Installation File

Mysqld_safe failed to start. it overwrites the my. cnf file under support-file to/etc/my. cnf, but the startup still fails. Go to data/machine name. err to view the log and find that the permission table is incorrect.After that, add mysqld to the

Create table t (A varchar (10));For this table, the results of the following two queries are the same by default:SELECT * FROM TABLE_NAME where a = 'abc ';SELECT * FROM TABLE_NAME where a = 'abc ';Mysql is case-insensitive. The solution to make

The blocking mechanism is mainly used to control concurrent operations and block interference to ensure data consistency and accuracy. There are three ways to block Oracle databases: Shared blocking, exclusive blocking, and shared update

Q: How can I solve the problem of too many mysql connections?A: The system cannot connect to the database. The key lies in two data points:1. Maximum number of connections allowed by the database system max_connections. This parameter can be set. If

Oracle claims that the installation of the Oracle9i database in Linux requires at least MB of memory and at least 1 GB or two times of memory swap space. For servers with a system memory larger than 2 GB, the swap space can be between 2 gb-4gb. If

This ordinary Thursday, like the past, goes to the company, opens a computer, and receives emails. In a few minutes, I received a text message with a mobile phone alarm. I checked it and put it there. I was able to receive hundreds of alarm messages

Today, when I wrote a Mysql Binlog-based refresh redis cache project, I just completed some functional development and the entire process went through. I suddenly found that the test machine had two versions of redis2.4.2 and redis2.6.2 installed on

After the data guard of Oracle is created, check the value of protection_mode and protection_level of v $ database. If the value of protection_mode is maximum availability, the value of protection_level should also be this value. If it is not the

I. AWR description Before 10 Gb, Oracle used the statspack tool to test the Database performance. Oracle Database 10 Gb provided a new tool: (AWR: Automatic Workload Repository ). Oracle recommends that you replace Statspack with this. AWR is

Handling of ORA-27101: shared memory realm does not exist Error ORA-01034 and ORA-27101 error messages when I try to connect to the database, it always displays such information, "ORA-01034-Oracle not available" and "ORA-27101-shared memory realm

Prerequisites: The info_user table contains the field id and name, and the field id is an index. The data_user_info table contains the field id and name, and the field id is an index. The field id in the info_user table is the same as the field

Two Methods for Oracle rename data files Note: red indicates the original path. Purple indicates the target path. First Alter tablespace users rename datafile '=' '***'; This method requires the database to be in the open state and the tablespace to

Create a tablespace in Oracle 1. Create a common tablespaceCreate tablespace oracle_tablespaceDatafile '/home/oracle/oradata/orcl/oracle_tablespace.dbf'Size 100 mAutoextend on next 10 M maxsize 200 MExtent management localUniform size 1 m; 2. Create

Generate execution plan After a valid statement is executed, at least one execution plan is generated in the memory, which can be queried from the view v $ SQL _plan. Each execution plan has a cursor. The CHILD_NUMBER (that is, the CHILD_NUMBER in v

. Use the srvctl command to configure the service   In addition to using DBCA graphics, you can also use commands to configure services. This method is especially useful for remote maintenance. Both creation and maintenance use the srvctl command.

Let's talk about the Oracle execution plan in detail today. The so-called execution plan is the execution plan made before a certain SQL statement is executed, or the execution path. There are two types of Oracle Optimizer models: RBO: Rule Based