New Things learing in 6 Months Internship

Amazon S3 Features Topics This section describes important Amazon S3 features. Storage Classes Amazon S3 offers a range of storage classes designed for different use cases. These include Amazon S3 STANDARD for general-purpose storage of frequently accessed data, Amazon S3 STANDARD_IA for long-lived, but less frequently accessed data, and GLACIER for long-term archive. For more information, see  Storage Classes . Bucket Policies Bucket policies provide centralized access control to buckets and objects based on a variety of conditions, including Amazon S3 operations, requesters, resources, and aspects of the request (e.g., IP address). The policies are expressed in our  access policy language  and enable centralized management of permissions. The permissions attached to a bucket apply to all of the objects in that bucket. Individuals as well as companies can use bucket policies. When companies register with Amazon S3 they create an  account . Therea...

Overview of Amazon S3 and This Guide Amazon S3 has a simple web services interface that you can use to store and retrieve any amount of data, at any time, from anywhere on the web. This guide describes how you send requests to create buckets, store and retrieve your objects, and manage permissions on your resources. The guide also describes access control and the authentication process. Access control defines who can access objects and buckets within Amazon S3, and the type of access (e.g., READ and WRITE). The authentication process verifies the identity of a user who is trying to access Amazon Web Services (AWS). Advantages to Amazon S3 Amazon S3 is intentionally built with a minimal feature set that focuses on simplicity and robustness. Following are some of advantages of the Amazon S3 service: Create Buckets  – Create and name a bucket that stores data. Buckets are the fundamental container in Amazon S3 for data storage. Store data in Buckets  – Store an i...

CARTESIAN JOIN : The CARTESIAN JOIN is also known as CROSS JOIN. In a CARTESIAN JOIN there is a join for each row of one table to every row of another table. This usually happens when the matching column or WHERE condition is not specified. In the absence of a WHERE condition the CARTESIAN JOIN will behave like a CARTESIAN PRODUCT . i.e., the number of rows in the result-set is the product of the number of rows of the two tables. In the presence of WHERE condition this JOIN will function like a INNER JOIN. Generally speaking, Cross join is similar to an inner join where the join-condition will always evaluate to True Syntax: SELECT table1.column1 , table1.column2, table2.column1... FROM table1 CROSS JOIN table2; table1 : First table. table2 : Second table SELF JOIN : As the name signifies, in SELF JOIN a table is joined to itself. That is, each row of the table is joined with itself and all other rows depending on some conditions. In other words we can say that it is a...

A SQL Join statement is used to combine data or rows from two or more tables based on a common field between them. Different types of Joins are: INNER JOIN LEFT JOIN RIGHT JOIN FULL JOIN The simplest Join is INNER JOIN. INNER JOIN:  The INNER JOIN keyword selects all rows from both the tables as long as the condition satisfies. This keyword will create the result-set by combining all rows from both the tables where the condition satisfies i.e value of the common field will be same. Syntax : SELECT table1.column1,table1.column2,table2.column1,.... FROM table1 INNER JOIN table2 ON table1.matching_column = table2.matching_column; table1 : First table. table2 : Second table matching_column : Column common to both the tables. Note : We can also write JOIN instead of INNER JOIN. JOIN is same as INNER JOIN. LEFT JOIN : This join returns all the rows of the table on the left side of the join and matching rows for the table on the right side of join. The rows ...