Introduction
to Oracle Database
An Oracle database is a collection of
data treated as a unit. The purpose of a database is to store and retrieve
related information. A database server is the key to solving the problems of
information management. In general, a server reliably manages a large amount of
data in a multi user environment so that many users can concurrently access the
same data. All this is accomplished while delivering high performance.
A
database server also prevents unauthorized access and provides efficient
solutions for failure recovery.
Oracle Database is the first database designed for
enterprise grid computing, the most flexible and cost effective way to manage
information and applications. Enterprise grid computing creates large pools of
industry-standard, modular storage and servers. With this architecture, each
new system can be rapidly provisioned from the pool of components. There is no
need for peak workloads, because capacity can be easily added or reallocated
from the resource pools as needed.
The database has logical structures and physical
structures. Because the physical and logical structures are separate, the
physical storage of data can be managed without affecting the access to logical
storage structures.
The Oracle grid architecture pools large numbers of
servers, storage, and networks into a flexible, on-demand computing resource
for enterprise computing needs. The grid computing infrastructure continually
analyzes demand for resources and adjusts supply accordingly.
For example, you could run different applications
on a grid of several linked database servers. When reports are due at the end
of the month, the database administrator could automatically provision more
servers to that application to handle the increased demand.
Grid computing uses sophisticated workload
management that makes it possible for applications to share resources across
many servers. Data processing capacity can be added or removed on demand, and
resources within a location can be dynamically provisioned. Web services can
quickly integrate applications to create new business processes.
Difference between a
cluster and a grid
Clustering is one technology used to create a
grid infrastructure. Simple clusters have static resources for specific
applications by specific owners. Grids, which can consist of multiple clusters,
are dynamic resource pools shareable among many different applications and
users.
A grid does not assume that all servers in the grid are running the same
set of applications. Applications can be scheduled and migrated across servers
in the grid. Grids share resources from and among independent system owners.
At the highest level, the idea of grid computing is
computing as a utility. In other words, you should not care where your data resides,
or what computer processes your request. You should be able to request
information or computation and have it delivered - as much as you want, and
whenever you want. This is analogous to the way electric utilities work, in
that you don't know where the generator is, or how the electric grid is wired,
you just ask for electricity, and you get it.
The goal is to make computing a
utility, a commodity, and ubiquitous. Hence the name, The Grid. This view of
utility computing is, of course, a "client side" view. From the "server side", or behind the
scenes, the grid is about resource allocation, information sharing, and high
availability.
Resource allocation ensures that all those that need or request
resources are getting what they need, that resources are not standing idle
while requests are going unserviced. Information sharing makes sure that the
information users and applications need is available where and when it is
needed. High availability features guarantee all the data and computation is
always there, just like a utility company always provides electric power.
Responsibilities of Database Administrators
Each database requires at least one database administrator (DBA). An Oracle
Database system can be large and can have many users. Therefore, database
administration is sometimes not a one-person job, but a job for a group of DBAs
who share responsibility.
A database
administrator's responsibilities can include the following tasks:
- Installing
and upgrading the Oracle Database server and application tools
- Allocating
system storage and planning future storage requirements for the database
system
- Creating
primary database storage structures (tablespaces) after application
developers have designed an application
- Creating
primary objects (tables, views, indexes) once application developers have
designed an application
- Modifying
the database structure, as necessary, from information given by
application developers
- Enrolling
users and maintaining system security
- Ensuring
compliance with Oracle license agreements
- Controlling
and monitoring user access to the database
- Monitoring
and optimizing the performance of the database
- Planning
for backup and recovery of database information
- Maintaining
archived data on tape
- Backing up
and restoring the database
- Contacting
Oracle for technical support
It's not uncommon for a DBA to earn as much as a
mid-level manager, and in larger shops the DBA is a vice president.
However, the high high pay is a double-edged sword. The DBA must
constantly justify their salary, and a good DBA who automates many of their job
functions may find themselves looking for a new job.
Here are some common questions that I'm asked about
becoming a DBA. Because most Oracle Applications databases support
mission critical systems, a successful Oracle Applications DBA must have these
skills:
·
Outstanding
Communications Skills - Oracle Applications DBA's must
interface with the end-user community and they must have college-level
communications skills, being able to communicate clearly, both orally and with
written communications.
·
Business Degree - Most successful
Oracle Applications DBA staff have advanced degrees in business administration,
almost all from AACSB accredited collegiate business schools. Graduates
of sub-optimal
business schools will have very difficult time obtaining a job
in Oracle Applications administration, and a firm understanding of business processes is
essential to perform many of the duties of the Oracle Applications DBA job
role.
·
DBA skills - Most Oracle
Applications DBA staff have at least five years of full-time progressive DBA
experience, and they sometimes have Oracle certifications such as OCP and OCM.
The Oracle Applications DBA must also have a good understanding of related
technologies, especially Java (JDeveloper, J2EE, Apache) and Oracle Application
Server.
What classes should I
take to prepare for a job as a DBA?
In grad school, all IT and CS students take courses like Operations
Research where they learn to develop complex decision rules and them apply them
to real world datasets. Using Oracle as the back-end storage of data and
decision rules is a great way to prepare for real-world applications of expert
systems, DSS and AI. Also, advanced statistics courses (multivariate
analysis) are a good way to prepare for a career in Oracle data mining and
Business Intelligence (BI). For details, see my notes on expert systems and
decision support systems using Oracle.
What College Degrees
are best for the DBA?
Companies are now requiring a combination of technical and managerial
skills and the best-fits are those with an undergraduate degree in Computer
Science and a MBA in Information Systems. Employers need a DBA who can
understand business systems areas (accounting, finance, and marketing) and
MBA's are a perfect fit for the DBA job role.
The hard-working kids who have distinguished themselves by graduating
from a top-tier university are aggressively courted by the major software
vendors (Oracle likes to
hire from Harvard, MIT, etc.).
Do I really need a Master’s
Degree to be a DBA?
Not always, but articles note that Tech jobs are
way-up for those with advanced degrees and Experts say IT
hiring up 40% for top college graduates.
Remember, there is a difference between working in database
administration and being "the" DBA, the person solely responsible for
the corporation’s data resources.
Ref: http://www.oracle-dba-online.com
http://www.dba-oracle.com/t_how_to_become_an_oracle_dba.htm
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