Deprecated

Features listed in this section should no longer be used, because they areconsidered obsolete and may get removed in a future release. They are currentlykept for backward compatibility. There are usually better alternatives toreplace the old features with:

  • MMFiles Storage Engine:The MMFiles storage engine is deprecated starting with version3.6.0 and it will be removed in a future release.To change your MMFiles storage engine deployment to RocksDB, see:Switch storage engine

We recommend to switch to RocksDB even before the removal of MMFiles.RocksDB is the default storage enginesince v3.4.0.

Once the MMFiles engine is removed, all MMFiles specific startup options willalso be removed. This will affect the following options:

  • —compaction.*
  • —database.force-sync-properties
  • —database.index-threads
  • —database.maximal-journal-size
  • —database.throw-collection-not-loaded-error
  • —wal.*The collection attributes doCompact, indexBuckets, isVolatile,journalSize and path are only used with MMFiles and are thus alsodeprecated.

  • Simple Queries: Idiomatic interface in arangosh to perform trivial queries.They are superseded by AQL queries, which can alsobe run in arangosh. AQL is a language on its own and way more powerful thanSimple Queries could ever be. In fact, the (still supported) _Simple Queries_are translated internally to AQL, then the AQL query is optimized and runagainst the database in recent versions, because of better performance andreduced maintenance complexity.

  • Actions: Snippets of JavaScript code on the server-side for minimalcustom endpoints. Since the Foxx revamp in 3.0, it became really easy towrite Foxx Microservices, which allow you to definecustom endpoints even with complex business logic.

From v3.5.0 on, the system collections _routing and _modules are notcreated anymore when the _system database is first created (blank new datafolder). They are not actively removed, they remain on upgrade or backuprestoration from previous versions.

You can still find theActions documentationin 3.4 or older versions of the documentation.