The document provides an overview of SQL window functions, specifically focusing on the over() clause that defines a set of rows for applying functions. It discusses various types of window functions such as ranking, aggregate, offset, and distribution functions, along with examples for each. The content emphasizes practical applications and provides source links for further reading.

1. SQL Tips
Window Functions – The OVER() Clause
June 4, 2014
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2. What is a Window Function?
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“A window function is applied to a set of rows defined
by a window descriptor and returns a single value for
each row from the underlying query.” – I. Ben-Gan
• Window Ranking functions (2005+)
• Window Aggregate Functions (2005+)
• Window Offset Functions (2012+)
• Window Distribution Functions (2012+)

3. The OVER() Clause
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• The OVER() clause is what defines the window
• Defines the set of rows that the function will
apply to
• PARTITION BY sets the boundaries for each set
of rows
• ORDER BY sets the order of the order for
ranking or offset functions within a given
partition

4. DEMOs
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• Ex 1 – 2005+ window aggregate using SUM()
and AVG()
• Ex 2 – 2005+ window ranking functions
– ROW_NUMBER()
– RANK()
– DENSE_RANK()
– NTILE(N)

5. DEMOs
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Do not copy, reproduce or distribute without the prior written consent of Insurance Auto Auctions.
• Ex 3 – 2012+ window aggregate using ordering
and framing
– ROWS BETWEEN UNBOUNDED AND
{CURRENT|PRECEEDING |FOLLOWING} ROW
– ROWS BETWEEN N
{CURRENT|PRECEEDING|FOLLOWING} AND N
{CURRENT|PRECEEDING|FOLLOWING}

6. DEMOs
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Do not copy, reproduce or distribute without the prior written consent of Insurance Auto Auctions.
• Ex 4 – 2012+ window offset functions
– LAG and LEAD
– FIRST_VALUE and LAST_VALUE
• Ex 5 – 2012+ window distribution functions
(statistical computations)
– Rank distribution
• PERCENT_RANK
• CUME_DIST
– Inverse Distribution
• PERCENTILE_DISC
• PERCENTILE_CONT

7. Sources
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Confidential and Proprietary Information of
Insurance Auto Auctions.
• http://sqlmag.com/sql-server-2012/how-use-microsoft-sql-
server-2012s-window-functions-part-1
• http://sqlmag.com/sql-server-2012/microsoft-sql-server-
2012-how-write-t-sql-window-functions-part-2
• http://sqlknowitall.com/?p=89