System Procedures

Table of Contents



System procedures are built-in procedures for inspecting and managing the engine: processes, transactions, locks, memory, health counters and security. They are run with Exec. Many of them require an administrator account.
  • Cancel - Cancels (rolls back) the transaction of the given process, leaving the process connected.
  • CheckpointHealthCounters - Writes the health counters to disk. This is useful when monitoring performance and you need the metrics in the health JSON file.
  • ClearCacheAllocations - Empties the engine's memory cache. The memory is kept allocated for future cache use; call ReleaseCacheAllocations afterwards to return it to the operating system.
  • ClearHealthCounters - Resets the health counters tracked by the engine. This is helpful when performance tuning.
  • Print - Evaluates an expression and returns the result as a message with the query results.
  • RefreshMyRoles - Reloads the role memberships of the logged in account. Roles are cached at login, so run this after your memberships change instead of logging out and back in. The roles are returned as messages.
  • ReleaseCacheAllocations - Returns unused cache memory to the operating system. Call ClearCacheAllocations first to release as much memory as possible.
  • ShowAggregateFunctions - Lists the built-in aggregate functions with their parameters and descriptions.
  • ShowBlocks - Shows which process is blocking each blocked process, optionally for a single process.
  • ShowBlockTree - Shows the tree of blocking processes, the processes they block and the resources being waited on. The tree is returned as a message.
  • ShowHealthCounters - Shows the health counters tracked by the engine, such as cache hits and misses and lock wait time.
  • ShowLocks - Shows every lock held by every transaction, optionally for a single process.
  • ShowMemoryUtilization - Shows the operating system's view of the memory used by the database engine.
  • ShowMySchemaPolicy - Shows the permissions that the logged in account has on a schema, and the role and schema each was inherited from.
  • ShowProcesses - Shows every connected process (session) with its session id, process id, client name and transaction state, optionally for a single process.
  • ShowScalarFunctions - Lists the built-in scalar functions with their parameters and descriptions.
  • ShowSchemaPolicy - Shows the security policy that applies to a schema: each permission, whether it is granted or denied, and the role and schema it was inherited from.
  • ShowSystemFunctions - Lists the built-in system procedures with their parameters and descriptions.
  • ShowThreadPools - Shows the threads of the engine's thread pools (lookup, indexing, intersection and materialization) and their processor usage.
  • ShowTransactions - Shows every active transaction, optionally for a single process.
  • ShowVersion - Shows the names and versions of the engine's assemblies, or of every loaded assembly when showAll is true.
  • ShowWaitingLocks - Shows the processes that are currently blocked waiting for a lock, optionally for a single process.
  • Sleep - Pauses the executing query for the given number of milliseconds. Useful for testing locking and timeouts.
  • Terminate - Terminates a process: rolls back its transaction, disconnects it and frees its resources. Kill does the same thing.