Technology Questions

The Data Definition Language (DDL) is used to manage table and index structure.

CREATE,

ALTER,

RENAME,

DROP and

TRUNCATE

statements are the names of few data definition elements.

The main differenc between View and Materialized View states that -

1. View means it stores the SQL statement in the database and let you use it as a table. Everytime you access the view, the SQL statement executes.

2. Materialized view means it stores the results of the SQL in table form in the database. SQL statement only executes once and after that everytime you run the query, the stored result set is used. Advantage include quick query results.

BUS Schema is composed of a master suite of confirmed dimension and standardized definition if facts.

Fact is key performance indicator to analyze the business.From the additive values, which are used to analyse the business by using report generation. Dimension is used to analyze the fact, are the non-additive ( text format) values, Which are used to drill down reports.Without dimension there is no meaning for fact. Measure is the quantity of data we create to process.

To be able to display the output directly to the browser, we have to use the special tags <?= and ?>.

In a SQL Database, a 'correlated subquery' is a kind of sub query yet connected subquery is dependent on another query for a value that is returned. In case of execution, the sub query is executed first and afterwards the correlated query will be executed.