Oracle

This article will explain Oracle Data Compression in two aspects: Using index keys to compress tables that are read-only or primarily read tables. Oracle supports the compression of index structures and database tables. The compression algorithms of

Part 5 LONG typeLONG is a type of data that has been discarded, and the LOB type is its alternative. So we will discuss it after LOB.We only need a simple understanding. Why does ORACLE retain this type, just for backward compatibility? In the new

We don't want to have every user install Oracle Data Access Components and drivers so we want to package it into our deployment. First dowload Oracle Data Access Components. The most current one as of 2/11/2011

Oracle JOB creation, scheduled task execution CNET China-PChome. net Type: Reproduced by: Unknown Source: China IT lab Editor: beiliang time: Begin Sys. dbms_job.submit (job =>: job, What => 'check _ err ;', Next_date => trunc (sysdate) plus

1. PrefaceCurrently, all applications that use Oracle for data processing are supported by Alibaba Cloud. Most of the systems with larger data volumes than other systems are supported, that is, the data volume of a table is generally larger than a

Use Truncate:Clear and recycle space (mysql, sqlserver, and other databases with auto-incrementing sequences return to zero). The database cannot be restored and cannot be rolled back; Use drop:The table can be restored but cannot be rolled

1. First, create a stored PROCEDURE in oracle. The stored PROCEDURE name library PROCEDURE prc_query Create or replace procedure prc_query(P_tableName in varchar2, -- table nameP_strWhere in varchar2, -- Query ConditionP_orderColumn in varchar2, --

Oracle Data Provider for. NET has two namespaces: Oracle. DataAccess. Client and Oracle. DataAccess. Types. Oracle. DataAccess. Client is used to set database connections and other general functions. Oracle. DataAccess. Types is used to set Custom

 Code Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/--> ---- Add and modify the check packageCreate or replace package TESTPACKAGE ISTYPE mycursor is ref cursor;Type mycursorid is ref cursor;Type

When I was doing a project, a colleague accidentally duplicate all the data in a table while importing data. That is to say, all the records in this table have a record. This table has tens of millions of data records and is a production system.

1. Basic concepts: Database connection strings are mainly used to establish access methods for remote databases. They can directly read or modify data in remote Oracle databases. The database connection string can be PUBLIC connection or PRIVATE

The logical structure of oracle includes tablespace, segments, data blocks, and schema objects ). Oracle databases are logically composed of multiple tablespaces, which physically contain one or more data files. The data file size is an integer

The process structure of the Oracle instance here refers to the process in the Unix system. In Windows, Oracle is an operating system service. An Oracle instance consists of a memory area and background process. Oracle instances are divided into

Chapter 6: load data     1.loading data using direct_load insert     sql> insert /*+append */ into emp nologging     sql> select * from emp_old;     2.parallel direct-load insert     sql> alter session enable parallel dml;    

Q. 1: This symbol, When you put infront of a line in the parameter file, signifies a comment 1. $2 .@3 .#4 .! 3 　　Q. 2: When you change a parameter value in the parameter file, when will that change takes affect? 1. Immediately after saving the

Chapter 1: Log Management     1.forcing log switches     sql> alter system switch logfile;     2.forcing checkpoints     sql> alter system checkpoint;     3.adding online redo log groups     sql> alter

Part 2: ORACLE Architecture[Q] which data types are available in ORACLE?[A] common data types include CHAR fixed-length character fields. The maximum length can be up to 2000 bytes. NCHAR multi-byte character sets have fixed-length character fields.

9.Simple Integration,No associated database access If you have several simple database query statements, you can integrate them into a single query (even if there is no relationship between them) For example: SELECT NAME FROM EMP WHERE emp_no. = 123

Oracle Materialized View The materialized view is like a real table for front-end database users. It has operations such as select that are similar to General tables, but it is actually a view, A view that is regularly refreshed by the system (the

Select a. tablespace_name, a. bytes bytes_used, B. largest, round (a. bytes-B. bytes)/a. bytes) * 100,2) percent_usedFrom (select tablespace_name, sum (bytes) bytes from dba_data_files group by tablespace_name),(Select tablespace_name, sum (bytes)