Thursday, 26 April 2018

Oracle DBA: Real Application Clusters (RAC)

1. Options for High Availability


Oracle has a Maximum Availability Architecture (MAA), which includes a combination of the options with Data Guard and RAC environments.

Monday, 23 April 2018

PL/SQL Control Structures

PL/SQL Control Structures


Procedural computer programs use the basic control structures.

Saturday, 21 April 2018

Database Backup, Restore, and Recovery

A backup is a copy of data from your database that can be used to reconstruct that data. Backups can be divided into physical backups and logical backups. Physical backups are backups of the physical files used in storing and recovering your database, such as datafiles, control files, and archived redo logs.

Thursday, 19 April 2018

SQL and PL/SQL Database

Structured Query Language (SQL)


SQL is a very simple, yet powerful, database access language. SQL is a non-procedural language; users describe in SQL what they want done, and the SQL language compiler automatically generates a procedure to navigate the database and perform the desired task.

Tuesday, 17 April 2018

PL/SQL Introduction

PL/SQL is a block structured language that enables developers to combine the power of SQL with procedural statements.All the statements of a block are passed to oracle engine all at once which increases processing speed and decreases the traffic.

Saturday, 14 April 2018

What is SQL Developer?

Oracle SQL Developer is the Oracle Database IDE. A free graphical user interface, Oracle SQL Developer allows database users and administrators to do their database tasks in fewer clicks and keystrokes. A productivity tool, SQL Developer's main objective is to help the end user save time and maximize the return on investment in the Oracle Database technology stack.

Wednesday, 11 April 2018

Introduction to Oracle SQL

Structured Query Language (SQL) is the set of statements with which all programs and users access data in an Oracle database. Application programs and Oracle tools often allow users access to the database without using SQL directly, but these applications in turn must use SQL when executing the user's request. This chapter provides background information on SQL as used by most database systems.

Tuesday, 10 April 2018

Control Invoker Rights Privileges for PL/SQL Code in Oracle Database 12c Release 1 (12.1) (INHERIT [ANY] PRIVILEGES)

Invoker rights procedures and functions can present a security risk by allowing privilege escalation if the contents of the procedure and functions are not checked for malicious code.

◈ The Problem


The following represents a scenario where a sneaky developer takes advantage of invoker rights to escalate their privileges.

Saturday, 7 April 2018

What is a NoSQL (Not Only SQL) Database?

A NoSQL database environment is, simply put, a non-relational and largely distributed database system that enables rapid, ad-hoc organization and analysis of extremely high-volume, disparate data types. NoSQL databases are sometimes referred to as cloud databases, non-relational databases, Big Data databases and a myriad of other terms and were developed in response to the sheer volume of data being generated, stored and analyzed by modern users (user-generated data) and their applications (machine-generated data).

Wednesday, 4 April 2018

Approximate Top-N Query Processing (APPROX_RANK, APPROX_SUM, APPROX_COUNT) In Oracle Database 18c

The APPROX_RANK, APPROX_SUM and APPROX_COUNT functions were introduced in Oracle 18c to allow approximate top-n query processing. This extends the approximate query processing that was introduced in the previous two releases (12cR1 and 12cR2).

Tuesday, 3 April 2018

Getting started with Oracle Database In-Memory Part III - Querying The IM Column Store

In my previous blog posts, I described how to install, enable, and populate the In-Memory column store (IM column store). This weeks post focuses on how data is accessed within the IM column store.

Let’s take a simple query “What is the most expensive air-mail order we have received to date?”

SELECT Max(lo_ordtotalprice) most_expensive_order