Operations: Server: How to Compact a Database

• Use the CompactDatabaseOperation to compact a database.
• You can choose what should be compacted: documents and/or listed indexes.

The compacting operation is executed asynchronously, and during this operation the database will be offline.

Syntax

// Define the compact settings
CompactSettings settings = new CompactSettings
{
  // Database to compact
  DatabaseName = "Northwind",
  
  // Setting 'Documents' to false will compact only the specified indexes
  Documents = false,
  
  // Specify which indexes to compact
  Indexes = new[] { "Orders/Totals", "Orders/ByCompany" }, 
  
  // Optimize indexes is Lucene's feature to gain disk space and efficiency
  // Set whether to skip this optimization when compacting the indexes
  SkipOptimizeIndexes = false
};

// Define the compact operation, pass the settings
IServerOperation<OperationIdResult> compactOp = new CompactDatabaseOperation(settings);

// Execute compaction by passing the operation to Maintenance.Server.Send
Operation operation = documentStore.Maintenance.Server.Send(compactOp);
// Wait for operation to complete
operation.WaitForCompletion();

// Get all indexes names in the database using the 'GetIndexNamesOperation' operation
// Use 'ForDatabase' if the target database is different than the default database defined on the store
string[] allIndexNames =
  documentStore.Maintenance.ForDatabase("Northwind")
      .Send(new GetIndexNamesOperation(0, int.MaxValue));

// Define the compact settings
CompactSettings settings = new CompactSettings
{
  DatabaseName = "Northwind", // Database to compact
  
  Documents = true,           // Compact all documents

  Indexes = allIndexNames,    // All indexes will be compacted
  
  SkipOptimizeIndexes = true  // Skip Lucene's indexes optimization
};

// Define the compact operation, pass the settings
IServerOperation<OperationIdResult> compactOp = new CompactDatabaseOperation(settings);

// Execute compaction by passing the operation to Maintenance.Server.Send
Operation operation = documentStore.Maintenance.Server.Send(compactOp);
// Wait for operation to complete
operation.WaitForCompletion();

Parameters
DatabaseName	string	Name of a database to compact
Documents	bool	Indicates if documents should be compacted
Indexes	string[]	List of index names to compact

Example I

// Get all member nodes in the database-group using the 'GetDatabaseRecordOperation' operation
List<string> allMemberNodes =
  documentStore.Maintenance.Server.Send(new GetDatabaseRecordOperation("Northwind"))
      .Topology.Members;

// Define the compact settings as needed
CompactSettings settings = new CompactSettings
{
  // Database to compact
  DatabaseName = "Northwind",
  
  //Compact all documents in database
  Documents = true
};

// Execute the compact operation on each member node
foreach (string nodeTag in allMemberNodes)
{
  // Define the compact operation, pass the settings
  IServerOperation<OperationIdResult> compactOp = new CompactDatabaseOperation(settings);
  
  // Execute the operation on a specific node
  // Use `ForNode` to specify the node to operate on
  Operation operation = documentStore.Maintenance.Server.ForNode(nodeTag).Send(compactOp);
  // Wait for operation to complete
  operation.WaitForCompletion();
}

Example II

// get all index names
string[] indexNames = store.Maintenance.Send(new GetIndexNamesOperation(0, int.MaxValue));

CompactSettings settings = new CompactSettings
{
  DatabaseName = "Northwind",
  Documents = true,
  Indexes = indexNames
};
// compact entire database: documents + all indexes
Operation operation = store.Maintenance.Server.Send(new CompactDatabaseOperation(settings));
operation.WaitForCompletion();

Example III

• CompactDatabaseOperation automatically runs on the store's database.
  If we try to compact a different database, the process will succeed only if the database resides on the cluster's first online node.
  Trying to compact a non-default database on a different node will fail with an error such as -
  "500 Internal Server Error : System.InvalidOperationException , Cannot compact database 'name' on node A, because it doesn't reside on this node."

• To solve this, we can explicitly identify the database we want to compact by providing its name to CompactDatabaseOperation as in the following example.

using (var store = new DocumentStore
{
  Urls = new[] { "http://localhost:8080" },
  Database = "sampleDB" // the store's database
}.Initialize())
{
  store.GetRequestExecutor().GetPreferredNode().Wait();

  const string DBToCompact = "NonDefaultDB"; // the database we want to compact
  string[] indexNames = store.Maintenance.Send(new GetIndexNamesOperation(0, int.MaxValue));

  var compactOperation = new CompactDatabaseOperation(new Raven.Client.ServerWide.CompactSettings
  {
      DatabaseName = DBToCompact,
      Documents = true,
      Indexes = indexNames
  });

  // Get request executor for our DB
  var reqEx = store.GetRequestExecutor(DBToCompact);

  using (reqEx.ContextPool.AllocateOperationContext(out var context))
  {
      var compactCommand = compactOperation.GetCommand(store.Conventions, context);
      reqEx.Execute(compactCommand, context);
  }
}