Oracle

Today, a colleague found me that his database is unusable, I hope I can help to study it.In fact, I do not have a database in-depth study, just when you like to look at the online master of the information, when things are customary to combine

1. Give one method for transferring a table from the schema to another:There is several possible methods, Export-import, CREATE TABLE ... As SELECT, or COPY.2. What is the purpose of the IMPORT option IGNORE? What is it?s default settingThe Import

1. What is a co-related subqueryA co-related subquery is one, have a correlation name as table or view designator in the FROM clause of the outer query And the same correlation name as a qualifier of a search condition in the WHERE clause of the

In Oracle Pl-sql, the left and right connections can also be implemented in the following wayExample:SELECT Stu_name, class_nameform students, Classeswhere students.classid (+) = Classes.idThe above SQL query uses the right connection.That is, the

1. Clustering factor algorithm:Locate the block number that corresponds to the record by Dbms_rowid.rowid_block_number (ROWID). rowID is recorded in the index, so Oracle can determine whether the record is in the same block based on the ROWID in the

Sql>startupError ora-00119ora-00130The above error should be the database listener file is out of the question, modify the Listener.ora file:# Listener.ora Network Configuration File:D:\app\WCWEN\product\11.2.0\client_2\NETWORK\ADMIN\listener.ora#

There is a need to divide the performance of the course into four grades for students to play a, B, C, D.drop table course purge;CREATE TABLE Course(ID number,Grade number);Insert into course values (1,50);Insert into course values (2,55);Insert

I. Oracle Common data types (other types are less common)(1) Character type1, char fixed length, maximum 2000 characters. For example: char (10) ' Xiao Ming ' first four words descriptors ' Xiao Ming ' after adding 6 blanks to complete. 2, VARCHAR2 (

A: PrefaceEvery time I export the data of Oracle data for backup is to read the statement, but also do not say that they knock more, but also skilled, but is not very reassuring, so the record down it.II: Content(1), the simplest, most direct import

Select Userenv (' language ') from dual;Simplified Chinese_china. Al32utf8Sql> Conn/as sysdba;sql> shutdown immediate;Database dismounted.sql> startup Mount;Total system global Area 135337420 bytesFixed size 452044 bytesVariable size 109051904

ObjectiveThis chapter is mainly about Oracle's architecture, which is also a strong theory. There are some more theoretical points of knowledge (such as table space AH), temporarily do not write, the next chapter began to enter the operational phase

Recently learned Oracle database with Oracle 10g (version: ORACLE_10G_10.2.0.1_WIN32) installed in a Windows XP SP3 system in a virtual machine.When the installation is complete, use PL/SQL developer to access the Oracle database and discover that

Server environment Requirementshard disk above 20G, must be higher than 1G of physical memory, swap space is generally twice times the memory, for example: 1G of memory can set the swap partition to 3G size  Under root user, perform the following

1. Import the Oracle database on the server to a localExecute the following command in CMD mode:Exp Username1/[email protected] Server-side database file= local hard disk:/file name. dmpFor example: Exp admin/[email protected] File=e:db.dmp2.

Solutions to oracle Scott account lock at the beginning 1. First, you need to unlock the Scott account and enter alter user scott account unlock. Then, a prompt is displayed, indicating that the scott account has expired and the password has

Step-by-step explanation of ORACLE (Lecture 3)I. Common oracle system functions1. Date Functions(1) to_date (string, Format) SQL> select to_date('2014-10-11 12:13:14','yyyy-mm-dd hh:mi:ss') from dual;TO_DATE('2014-10-1112:13:14','--------------------

Oracle analysis function ntile With such A requirement, the scores of the course are divided into four levels to provide A, B, C, and D Performance for students. Drop table course purge; create table course (id number, grade number); insert into

After the oracle splits the string, it is displayed in a single column and multiple rows. Original SQL: Select substr (field1, instr (field1, '|', 1, rownum) + 1, instr (field1, '|', 1, rownum + 1)-instr (field1, '|', 1, rownum)-1) as field2 from (

Summary of methods for detecting ORACLE data block corruption 1: Use initialization parameters You can use the initialization parameter db_block_checksum \ db_block_checking to set the database's physical consistency and logical consistency check

Oracle _ sequence, index, synonymZookeeper 1. Sequence1. sequence: database objects that can be used by multiple users to generate unique valuesUnique value automatically providedShared objectIt is mainly used to provide the primary key