Database Administrator

In Linux, the database name, table name, column name, And alias are case-sensitive: 1. The database name and table name are case sensitive; 2. Table aliases are case sensitive; 3. The column name and column alias are case-insensitive in all cases;

Installing Oracle RAC on the AIX platform is a pitfall. I verified this again today because there are too many bugs! Record the problem because there are too many bugs! We strongly recommend and look forward to the development of Oracle RAC on the

Oracle multi-Table query, as its name implies, queries the data you want from multiple tables. Here we will test the emp table and dept table under the scott user. The structure of the two tables is as follows: SQL> select * from dept;DEPTNO DNAME

Installation environment: Oracle_HOME =/home/oracle/product/11.2.0/db_1 The ORACLE_HOME/network/admin/listener. ora file is as follows: # Listener. ora Network Configuration File:/home/oracle/product/11.2.0/db_1/network/admin/listener. ora #

1. Introduction In relational databases, join operations are common when data in different tables are joined. First, let's take a look at how the join operation works. Then, let's explore the execution sequence when the join and where statements

As the application complexity increases, database segmentation is constantly refined, resulting in complicated and messy database applications in applications. Most programmers may encounter this situation, and the application needs to connect to

Someone recently proposed to view the Postgresql execution plan. The following describes how the cost and other related values in the PG execution plan are calculated:PG version 9.1.21. Use the terminal tool PGADMIN to press F7 to execute the

Sometimes the development of table structure design, whether the table field is empty is too casual, such as id1 = id2, if the field is allowed to be empty, because the Oracle empty value is not equal to the null value, unexpected results may be

1. scenario description;Catalog database 192.168.1.206: 1521 gridTarget database 192.168.1.201: 1521 ql2. Create the rman tablespace on the catalog database SQL> create tablespace rman datafile '/u01/app/Oracle/oradata/gird/rman. dbf' size 500 m

MySQL Replication We know that the binary log of the MySQL database records every clear or potentially changing SQL statement of the database. Therefore, we can achieve the master-slave consistency of mysql based on the binary log. The simple mysql

Fine-grained auditing (FGA) is introduced in Oracle 9i. It can record SCN numbers and row-level changes to recreate old data, However, they can only be used for select statements, but not for DML, such as update, insert, and delete statements.

1. Description of Invisible Indexes Oracle can create invisible indexes starting from version 11g. The OPTIMIZER_USE_INVISIBLE_INDEXES initialization parameter is explicitly set to TRUE, unless invisible indexes are ignored. The default value of

Using shell scripts to monitor and manage Oracle databases will greatly simplify DBA workload, such as common instance monitoring, monitoring, and alarm log monitoring, and database backup, AWR report automatic mail, etc. This article describes how

Redis is a high-performance key-value database. The emergence of redis largely compensates for the shortage of keyvalue storage such as memcached, and can play a very good complementary role in relational databases. It provides Python, Ruby, Erlang,

Oracle does not have the date () function. The sysdate function value includes the time, minute, and second. It is really troublesome to insert the default value of the current time. You have to write the stored procedure on your own, and you cannot

Introduction Hash table is one of the core structures of redis. In redis source code, dict. c and dict. h defines the hash structure used by redis. In this article, we will. c and dict. h. Because dict. the implementation of the separate chaining

What is PL/SQL?• PL/SQL is a programming Language developed by Oracle and dedicated to Oracle • PL stands for ProceduralLanguage • SQL stands for StructuredQuery Language • PL/SQL is an Oracle database extension of SQL statements, added programming

Oracle 10gBasic Database Query statements-above--Reference: Zhang lie Zhang Jianzhong Database Administrator training handout Principles for writing SQL statements The case is not sensitive, but the case sensitivity of single and double quotes.

Use this SQL statement Select*FromTree View the raw data as follows: The following figure shows the result of a tree query (including the fields ROOT, LEVEL, IS_LEAF, and PATH ): Execute the following SQL statement: SelectConnect_by_root

This article mainly introduces the installation of Oracle 11g RAC and the creation and migration of 10g databases in the 11g RAC environment, and how to upgrade the database to the 11g version. The architecture of the 11g RAC and some new features