The Ultimate Guide to High Availability with MariaDB

SQL Server features not available in MariaDB

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Contents

  1. Introduced in SQL Server versions older than 2016
  2. Introduced in SQL Server 2016
  3. Introduced in SQL Server 2017
  4. Introduced in SQL Server 2019

When planning a migration between different DBMSs, one of the most important aspects to consider is that the new database system will probably miss some features supported by the old one. This is not relevant for all users. The most widely used features are supported by most DBMSs. However, it is important to make a list of unsupported features and check which of them are currently used by applications. In most cases it is possible to implement such features on the application side, or simply stop using them.

This page has a list of SQL Server features that are not supported in MariaDB. The list is not exhaustive.

Introduced in SQL Server versions older than 2016

  • Full outer joins
  • GROUP BY CUBE
  • MERGE
  • In MariaDB indexes are always ascending, even if defined as DESC
    • For single-columns indexes, the performance difference between an ORDER BY ... ASC and DESC is negligeable.
    • For multiple-columns indexes, an index may be unusable for certain queries because DESC is not supported. In some cases, a generated column can be used to invert the order of an index (for example, the expression 0 - price can be indexed to index the prices in a descending order).
  • User-Defined Types
  • Rules
  • Triggers on DDL and login; INSTEAD OF triggers, DISABLE TRIGGER
  • Cursors advanced features
    • Global cursors
    • DELETE CURRENT OF, UPDATE CURRENT OF (MariaDB cursors are dead-only)
    • Specifying a direction (MariDB cursors can only advance by one row)
  • Filtered indexes
  • Synonyms
  • Queues
  • XML indexes, XML schema collection, XQuery
  • User access to system functionalities, for example:
    • Running system commands (xp_cmdshell())
    • Sending emails (sp_send_dbmail())
    • Sending HTTP requests
  • External languages, external libraries (MariaDB only supports procedural SQL and PL/SQL)

Introduced in SQL Server 2016

  • PolyBase (however, MariaDB supports accessing Amazon S3 via the S3 storage engine and several DBMSs via CONNECT)
  • R services

Introduced in SQL Server 2017

  • Adaptive joins
  • Graph SQL

Introduced in SQL Server 2019

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