What algorithms does SQL use? [closed]

Answer 1

I would suggest you get a copy of SQL Server 2008 Internals by Delaney, Randal, Tripp and more. Excellent book on the internal workings of SQL Server.

http://www.amazon.com/Microsoft-SQL-Server-2008-Internals/dp/0735626243/ref=sr_1_1?s=books&ie=UTF8&qid=1289565465&sr=1-1

Answer 2

You can take a look at the Microsoft blog about SQL Server Query Processing, which discusses some SQL Server internals. (The originally linked Craig Freedman blog has been moved there.) Just browse for the interesting topics. If I understood it right, he also wrote some chapter for the already mentioned book series "SQL Server Internals".

You can search the above linked site for the following topics to shed some light on how the different JOIN algorithms work internally:

• Nested Loop Join
• Hash Join
• Merge Join

Answer 3

Joins are performed in three methods: 1. Nested Loop 2. Hash 3. Merge

Get more about these join methods here:

http://www.sqlservercentral.com/articles/Advanced+Querying/optimizerjoinmethods/1708/

Answer 4

SQL is a superset of relational algebra. At its basic level, you might want to become familiar with that some. Relational Algebra

Answer 5

RDBMS composed of several elements:

• Transaction manager -- manages transactions, as evident from it's name:)
• Physical storage manager -- manages how data stored in underlying file-system(s)
• Query parser/planner/executor -- this is 'user front-end' of database

Each of these elements is essential for any RDBMS and use different set of algorithms to make itself work.

If you interested in internals of RDBMS, get yourself this book: http://www.amazon.com/Database-Systems-Complete-Book-2nd/dp/0131873253/