Management of 1.Oracle Tables
Naming conventions for table and column names:
Must start with a letter;
Length cannot exceed 30 characters;
Cannot use Oracle's reserved words;
Use only the following characters: A-Z, A-Z, 0-9,
One. Query article
1. Query Oracle Table space usage
Select b.file_id file ID,
B.tablespace_name table Space,
B.file_name Physical file name,
The total number of bytes b.bytes,
(B.bytes-sum (NVL (a.bytes,0))) has been used,
Sum (NVL (a.bytes,0))
For a database, each table actually represents a database object, and the database object refers to all the operations defined by DDL, for example: tables, views, indexes, sequences, constraints, and so on all belong to object operations. Therefore,
Note: This article declined to reprint.1 managing table spaces in a CDBCDB table space management and NON-CDB table space management, CDB also has an instance, specified at the time of installation.-- To view a table space:Sql> Select instance_name
Oracle basic concepts and comparison with informix
I. ConceptsUser: informix directly uses the user management system of the operating system. Generally, root and informix are used as super operators to manage other users. Oracle has its own user
Oracle
[Oracle] History of the Oracle ――oracle company legend
Author: fenng
Date: Sep 09 2004
The origins of Oracle Company
It is hard to imagine the Oracle Company's saga starting with IBM.
1970 June, IBM researcher Edgar Cauter (Edgar Frank
The racle database system is a complex software system. Without understanding its internal structure principles and relationships, it is impossible to design and Compile High-Quality application software systems or manage a complex application
Http://www.itpub.net/thread-1478468-1-1.html
Http://tomszrp.itpub.net/post/11835/520574
Since version 11.2.0.1, Oracle has provided a new space allocation method: When you create a non-partition table, this table segment is not created immediately,
ORACLE External table Summary, ORACLE table Summary
External table Introduction
ORACLE External tables are used to access Text files (Text files) other than databases or ORACLE exclusive format files. Therefore, when an External table is created,
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