#Md5 encoding in sql how to#
#Md5 encoding in sql code#
#Md5 encoding in sql windows#

If your dataset is mostly in this character range then using UTF-16 is preferred. HASH joins/LIKE/Inequality comparisons will perform slightly better in UTF-8 for the same dataset.īut Chinese, Japanese, or Korean characters are represented starting in the range 2048 to 65535, and use 3 bytes in UTF-8, but only 2 bytes in UTF-16. This is because a few internal conversions happen during these operations. When using compute-intensive operations such as SORTs/MERGE joins then UTF-16 is generally better than UTF-8 for the same dataset. Performance measurements were very similar between UTF-8 and UTF-16 in this range.

What if your dataset is not predominately ASCII? Above the ASCII range, almost all Latin alphabets, but also Greek, Cyrillic, Coptic, Armenian, Hebrew, Arabic, Syriac, Tāna and N’Ko will use 2 bytes per character in both UTF-8 and UTF-16 (128 to 2047). In the ASCII range, when doing intensive read/write I/O on UTF-8, we measured an average 35% performance improvement over UTF-16 using clustered tables with a non-clustered index on the string column, and an average 11% performance improvement over UTF-16 using a heap. This is because NCHAR(10) requires 22 bytes for storage, whereas CHAR(10) requires 12 bytes for the same Unicode string. If your dataset uses primarily ASCII characters (which represent majority of Latin alphabets), significant storage savings may be achieved as compared to UTF-16 data types.įor example, changing an existing column data type from NCHAR(10) to CHAR(10) using an UTF-8 enabled collation, translates into nearly 50% reduction in storage requirements. Performance differences between UTF-8 and UTF-16 The table below outlines these storage boundaries:

#Md5 encoding in sql code#

But UTF-16 uses at least 16-bits for every character in code points 0 to 65535 (available in UCS-2 and UTF-16 alike), and code points 65536 to 1114111 use the same 4 bytes as UTF-8.The code points 65536 to 1114111 use 4 bytes, and represent the character range for Supplementary Characters. ASCII characters (0-127) use 1 byte, code points 128 to 2047 use 2 bytes, and code points 2048 to 65535 use 3 bytes. UTF-8 encodes the common ASCII characters including English and numbers using 8-bits.However, there are important differences that drive the choice of whether to use UTF-8 or UTF-16 in your multilingual database or column:

UTF-8 and UTF-16 both handle the same Unicode characters, and both are variable length encodings that require up to 32 bits per character. SELECT Name, Description FROM fn_helpcollations()įunctional comparison between UTF-8 and UTF-16 You can see all available UTF-8 collations by executing the following command in your SQL Server 2019 instance:

#Md5 encoding in sql windows#

Like UTF-16, UTF-8 is only available to Windows collations that support Supplementary Characters, as introduced in SQL Server 2012. Note that NCHAR and NVARCHAR remains unchanged and allows UCS-2/UTF-16 encoding.

#Md5 encoding in sql how to#

Refer to Set or Change the Database Collation and Set or Change the Column Collation for more details on how to perform those changes. String data is automatically encoded to UTF-8 when creating or changing an object’s collation to a collation with the “_UTF8” suffix, for example from LATIN1_GENERAL_100_CI_AS_SC to LATIN1_GENERAL_100_CI_AS_SC_UTF8. To limit the amount of changes required for the above scenarios, UTF-8 is enabled in existing the data types CHAR and VARCHAR. The benefits of introducing UTF-8 support also extend to scenarios where legacy applications require internationalization and use inline queries: the amount of changes and testing involved to convert an application and underlying database to UTF-16 can be costly, by requiring complex string processing logic that affect application performance. This is an asset for companies extending their businesses to a global scale, where the requirement of providing global multilingual database applications and services is critical to meet customer demands, and specific market regulations. This has been a longtime requested feature and can be set as a database-level or column-level default encoding for Unicode string data. SQL Server 2019 introduces support for the widely used UTF-8 character encoding.