How SQL database works internally?

How does SQL works internally?

SQL Query mainly works in three phases . 1) Row filtering - Phase 1: Row filtering - phase 1 are done by FROM, WHERE , GROUP BY , HAVING clause. 2) Column filtering: Columns are filtered by SELECT clause. 3) Row filtering - Phase 2: Row filtering - phase 2 are done by DISTINCT , ORDER BY , LIMIT clause.

How does database work internally?

Databases use a B-tree data structure to store indexes to improve the performance of the database. Data records are stored in a B+tree structure. If no indexing use, only B+tree used to store the data. A cursor is a special pointer which used to point a record( or row) which given with page id and offset.

How does SQL work in a database?

SQL is the most common language for extracting and organising data that is stored in a relational database. A database is a table that consists of rows and columns. SQL is the language of databases. It facilitates retrieving specific information from databases that are further used for analysis.

How data is stored internally in SQL Server?

SQL Server data is stored in data files that, by default, have an . MDF extension. The log (. LDF) files are sequential files used by SQL Server to log transactions executed against the SQL Server instance (more on instances in a moment).