Base De Datos

1. Uso de DBMS
1 Introducción
1.1 Definición
DBMS Database Management System
Colección de datos interrelacionados y un conjunto de programas para acceder a esos datos
1.2 Componentes de un DBMS
• Data definition language (DDL):
Define elementos de los datos en la base de datos
• Data manipulation language (DML):
Manipula datos para aplicaciones
• Data dictionary:
Definiciones detodas las variables en la base

2 DBMS más populares
2.1 Ejemplos
Logo Nombre URL Productos
Sybase www.sybase.com Adaptive Server
Oracle www.oracle.com Oracle8, Oracle8i, Oracle8iEE, Oracle9i, Oracle 10g
PostgreSQL www.postgresql.org PostgreSQL
Microsoft www.microsoft.com Access, MS-SQL Server
MySQL www.mysql.com MySQL
Informix www.informix.com
Illustra, Universal Server,Dynamic Server
IBM www.ibm.com DB2
Apache http://db.apache.org/derby
Derby
SQLite http://www.sqlite.org SQLite
Firebird http://firebird.sourceforge.net Firebird


2.2 Principales Diferencias entre DBMS
2.2.1 Diferencias
Costo
”Gratuitos”:
MySQL, PostgreSQL, mSQL, Interbase
Comerciales:
DB2, Sybase, Informix, Oracle
Otros de dominio público:http://www.faqs.org/faqs/databases/free-databases/ Técnicas
• Sub-selects
• Select into table
• Transactions
• UDF (user defined functions)
• Foreign keys
• Views
• Tipos de Datos
• Manejo de memoria (Virtual Memory, Shared Memory)
• Manejo de disco (Archivos, Chunks)
2.2.2 Costos de Oracle (2000)
Cotizando Oracle
Example 1: You are licensing the Oracle8iEE for a computer which has
2 - 400MHz RISCprocessors.
How many Universal Power Units do you need?
(1 computer x 2 processors * 400MHz * 1.5 (RISC Factor) = 1,200 Universal Power Units for each program that you license for this computer.
Example 2: You are licensing Oracle8iEE for your entire environment -
4 Intel computers each with a 550MHz Intel processor;
1 computer with 8 - 400MHz RISC processors.
How many Universal Power Units do youneed?
4 computers x 1 processor x 550MHz x 1.0 (Intel Factor)=2,200 UPU
1 computer x 8 processors x 400MHz x 1.5 (RISC Factor)=4,800 UPU Total: 7,000 UPU
Example 3: You have a mainframe computer that has 200 MIPS and are licensing Oracle8iEE.
How many Universal Power Units do you need?
1 computer x 200 MIPS x 24 (Mainframe Factor) = 4,800 UPUs are required
Pricing
Case 1
For Oracle8i (you can get 5%-10% off the list price, but that about it) take the UPU and muiltiply by:
Perpetual $15.00
4 Year(lease) 9.00
2 year (lease) 5.25
Example:
2 Sun ULTRA10 with 450mhz 2*450*1.5=1350 upu
1350upu*$15= $20,500 usd
And do not forget about 15% or so per year for support.
Support (each year) $ 3,075 usd

Case 2
Now if you have more than 2 cpu's (they force you) or wantOracle 8iEE (all the good stuff)
Perpetual $100.00
4 Year(lease) 60.00
2 year (lease) 35.00
1350upu* $100= $ 135,000 usd for 8iEE
And do not forget about 15% or so per year for support.
Support (each year) $ 20,250 usd

Más cotizaciones de Oracle aquí
2.2.3 Escogiendo la combinación perfecta
Consideraciones al elegir un DBMS
• Número de usuarios
• Número de transacciones
•Cantidad de datos para almacenar
• Consistencia en la información
• Presupuesto
• Experiencia propia o externa*

*SQL Server, Informix, Oracle
SQL server is OK for very small installations. Do not try to run a major
organization on this product. If horsepower (CPU number crunching for
example) is required, move on to the real relation databases.
Oracle is popular, expensive, global in itsreach, and can do most any thing
you need, (for a small fee). It tends to be more labour intensive then
INFORMIX, and from my experience crashes far too often for my taste. You will
hardly ever find an Oracle DBA alone. Be careful, because Oracle has the best
marketing going right now, not necessarily the best product. Sort of like MS.
Informix is fast, scalable ,affordable,stable if you...