SQL * Plus is an environment provided by Oracle for users to use SQL statements and its procedural language PL/SQL to interact with the database. It is installed with the Oracle database system. In this environment, you can use SQL and PL/SQL statements to create and manage all objects in the database. SQL * Plus is a tool based on a two-layer structure, mainly including: Customer layer: Command Line User Interface/graphical interface. · Database layer: Oracle database. The two layers can be either on the same host or on the same host. Oracle also provides layer-3 iSQL * Plus, which does not need to be installed separately. It accesses the database through a browser. ISQL * Plus Three-tier model, as shown in 3-1. Figure 3-1 three-tier model of iSQL * Plus-customer layer: iSQL * Plus user interface, which is a typical web browser. · Intermediate layer: including iSQL * Plus application server, Oracle Net, and Oracle HTTP Server. · Database layer: Oracle database. ISQL * Plus is installed and configured with Oracle 10 Gb. After the installation is complete, it appears in the form of oracleoradb 10g_home1isql * Plus service in the Windows service. To manage iSQL * plus, you only need to execute isqlplussvc.exe-start 5580in the ms-doscommand prompt to start the service worker and execute isqlplussvc.exe-stop to stop the service. The iSQL * Plus user interface runs in a web browser. You do not need to install and configure it separately. To start iSQL * Plus, you can find its URL in the readme.txt file of oracle_base/ORACLE_HOME/installdirectory. For example, the URL of D:/Oracle/product/10.2.0/db_1/install is http: // localhost: 5560/isqlplus, And the portlist. ini file stores the detailed port number for installation. The customer layer has many development tools related to SQL and PL/SQL. Among them, RMAN (rediscovery manager) is the most practical tool for database backup and recovery, in addition to completing database backup, recovery, start and close functions, you can also execute any SQL commands and PL/SQL blocks. Rman must be started in the MS-DOS prompt. Chapter 3rd of SQL and PL/SQL use environments in addition, there are many other manufacturers that produce Oracle-related development tools, such as toad (tools of Oracle Application Developer) and PL/SQL developer, they all have the same features as SQL * Plus, and even have many features that SQL * Plus does not have.
