Oracle

Before the installation of Oracle, but also deliberately found a few blog and Baidu experience to see, because know that Oracle can only install once, if not installed, OK, the basic exclusion of the installation of the possible (installation of

The shared pool can be said to be a very important power resource in the database, which is related to the performance bottleneck of the database.what is a shared pool? The shared pool is part of the SGA (System global Zone) in the memory structure,

1. Assign permissions with DBA LoginCreate or replace directory D_output as ' D:\TEMP ';Grant Read,write on directory d_output to TestDB;GRANT EXECUTE on Utl_file to TestDB;2. Write a function to create the directory and write the dataCalling

Oracle's execution planHow to get the plan executedAutotrace ExampleUsing explainExplain plan set statement_id= ' Testplan ' for select * from dual;Select Lpad (", 5* (level-1)) | | Operation operation, Options, object_name, cost,position from

Organize and organize the knowledge of Oracle. Hope to be of help to everyone.The startup process for an Oracle DB instance is divided into 3 steps: Launch the instance, load the database, and open the database.STARTUP [Nomount | mount | open |

Oracle Series: Record RecordsClassification:"Oracle" (a) Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.Oracle series: Records (record)One, what is a record? A composite structure

I. INTRODUCTION OF TriggersThe definition of a trigger is that when a condition is established, the statements defined in the trigger are automatically executed. Therefore, the trigger does not need to be called artificially, nor can it be called.

1. FunctionsCreate or Replace function Gettablecount (table_name VARCHAR2) return number asBeginDECLARE sql_query VARCHAR2 (300);T_count number;Begin 　　　　　　Sql_query:= ' SELECT COUNT (*) from ' | |   table_name; There is a space behind the

Schema is a collection of database objects, in order to differentiate the collection, we need to give this collection a name, these are the many similar user names that we see under the Enterprise Manager scenario, these nodes are actually a Schema, 

One, sys users and system usersThe Oracle installation automatically generates SYS users and system users(1), sys user is superuser, has the highest privileges, has the SYSDBA role, has the rights to create database, the user's default password is

The following document DBCA the process of creating the main library, with pictures in each of the basic steps. Oracle User Execution DBCA, if it is the root user login graphics surface, the SU switch user before need to execute a xhost +x,

Sometimes because the logfile is too small, resulting in log switching frequently, causing the log file switch ... Wait for the event, this time need to increase the size of the logfile.To increase the size of the logfile:One: View initialization

recently the system often locks the table every day, and after the process has been killed, it is locked again soon. (a) First post the process of the scene to deal with the deadlock.In addition: Sometimes the kill session through PL/SQL may still

1: Catch exception thrown by PlsqlDeclareV_ename Emp.ename%type;BeginSelect Ename to V_ename from EMP where empno=10;exceptionWhen Too_many_rows ThenDbms_output.put_line (' Too many values ');When others thenDbms_output.put_line (' error ');End/2:

This article has been redirected from an excessive number of Oracle Dblink connections (Ora-02020)Today, when dealing with data synchronization issues, it is necessary to synchronize data from several other DB servers to a single target repository,

SQL statements are executed serially on a single CPU (Serial), even if there are multiple CPUs in the system, and an SQL statement cannot take advantage of them. This allows a CPU to use resources that determine the performance of the SQL statement.

Using JDBC to connect to the database, fly is divided into three steps:The first step: Download a JDBC driver, then throw the jar package into the project and add to build path;Step two: Go to the local Oracle folder to find "TNSNames." ORA "file,

In fact, this is not a new topic. But before in many projects, always encountered in the Oracle database access, there will be a variety of problems, the most basic is to install a variety of clients on the client, the version is different, there

Delete (delete a record)Drop or truncate delete data from a table1.delete Solution for accidental deletionPrinciple: Using the Flashback method provided by Oracle, if you have not done a lot of operations after deleting the data (as long as the

Oracle instances and Oracle databases (Oracle Architecture) -- ===================================================== === -- Oracle instance and Oracle Database (Oracle Architecture) -- ===================================================== === /* For