decompress-transact-sql.md

title	DECOMPRESS (Transact-SQL) | Microsoft Docs
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ms.date	11/30/2015
ms.prod	sql
ms.prod_service	database-engine, sql-database
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ms.suite	sql
ms.technology	t-sql
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ms.topic	language-reference
f1_keywords	DECOMPRESS DECOMPRESS_TSQL
helpviewer_keywords	DECOMPRESS function
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author	MashaMSFT
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DECOMPRESS (Transact-SQL)

[!INCLUDEtsql-appliesto-ss2016-asdb-xxxx-xxx-md]

This function will decompress an input expression value, using the GZIP algorithm. DECOMPRESS will return a byte array (VARBINARY(MAX) type).

Transact-SQL Syntax Conventions

Syntax

DECOMPRESS ( expression )  

Arguments

expression
A varbinary(n), varbinary(max), or binary(n) value. See Expressions (Transact-SQL) for more information.

Return Types

A value of data type varbinary(max). DECOMPRESS will use the ZIP algorithm to decompress the input argument. The user should explicitly cast result to a target type if necessary.

Remarks

Examples

A. Decompress Data at Query Time

This example shows how to return compressed table data:

SELECT _id, name, surname, datemodified,  
             CAST(DECOMPRESS(info) AS NVARCHAR(MAX)) AS info  
FROM player;  

B. Display Compressed Data Using Computed Column

This example shows how to create a table for decompressed data storage:

CREATE TABLE example_table (  
    _id int primary key identity,  
    name nvarchar(max),  
    surname nvarchar(max),  
    info varbinary(max),  
    info_json as CAST(decompress(info) as nvarchar(max))  
);  

See Also

String Functions (Transact-SQL)
COMPRESS (Transact-SQL)