What is the difference between MySQL and Oracle?

Vaibhav Kothia May 30, 2023 0 Comments

MySQL and Oracle are two of the most popular relational database management systems (RDBMS).

The main difference between MySQL and Oracle is that MySQL is an open-source RDBMS, while Oracle is a proprietary RDBMS owned by Oracle Corporation. MySQL is based on the Structured Query Language (SQL), while Oracle is based on the PL/SQL language. MySQL is typically used for web-based applications, while Oracle is used for larger applications and data warehouses.

Example:

MySQL:

MySQL is used to manage web-based applications such as content management systems, blogs, and forums. It is also used for data analysis and reporting.

Oracle:

Oracle is used for larger applications such as enterprise resource planning (ERP) systems, customer relationship management (CRM) systems, and data warehouses. It is also used for data mining and predictive analytics.

What are the different types of tables in Oracle?

Vaibhav Kothia May 26, 2023 0 Comments

1. Heap-Organized Tables: These are the most common type of tables in Oracle. They are organized as a heap, which means that data rows are stored in an unordered fashion. For example, a table named “EMPLOYEES” can be created with the following command:

CREATE TABLE employees (
employee_id INTEGER,
first_name VARCHAR2(50),
last_name VARCHAR2(50),
email VARCHAR2(50),
salary NUMBER
);

2. Index-Organized Tables: These tables are organized based on an index. This means that the data is stored in an ordered fashion based on the index key. For example, a table named “ORDERS” can be created with the following command:

CREATE TABLE orders (
order_id INTEGER,
customer_id INTEGER,
order_date DATE,
order_total NUMBER,
CONSTRAINT orders_pk PRIMARY KEY(order_id)
) ORGANIZATION INDEX;

3. Clustered Tables: These tables are organized based on a cluster key. This means that the data is stored in an ordered fashion based on the cluster key. For example, a table named “PRODUCTS” can be created with the following command:

CREATE TABLE products (
product_id INTEGER,
product_name VARCHAR2(50),
product_price NUMBER,
CONSTRAINT products_pk PRIMARY KEY(product_id)
) CLUSTER product_cluster(product_name);

4. Temporary Tables: These tables are used to store temporary data. They are usually created and populated with data for a specific purpose and then dropped when no longer needed. For example, a table named “TEMP_DATA” can be created with the following command:

CREATE GLOBAL TEMPORARY TABLE temp_data (
data_id INTEGER,
data_value VARCHAR2(50)
);

How do you create a database in Oracle?

Vaibhav Kothia May 26, 2023 0 Comments

In Oracle, you can create a database by using the CREATE DATABASE statement.

For example, the following statement creates a database named “testdb” with the default settings:

CREATE DATABASE testdb;