decompress-transact-sql.md

description	DECOMPRESS (Transact-SQL)
title	DECOMPRESS (Transact-SQL) | Microsoft Docs
ms.custom
ms.date	10/11/2018
ms.prod	sql
ms.prod_service	database-engine, sql-database
ms.reviewer
ms.technology	t-sql
ms.topic	reference
f1_keywords	DECOMPRESS DECOMPRESS_TSQL
helpviewer_keywords	DECOMPRESS function
ms.assetid	738d56be-3870-4774-b112-3dce27becc11
author	cawrites
ms.author	chadam

DECOMPRESS (Transact-SQL)

[!INCLUDE sqlserver2016-asdb-asdbmi-asa]

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)