Compact Database Operation


  • Use The CompactDatabaseOperation compaction operation to removes empty gaps on disk that still occupy space after deletes.
    You can choose whether to compact documents and/or selected indexes.

  • During compaction the database will be offline.
    The operation is a executed asynchronously as a background operation and can be awaited.

  • The operation will compact the database on one node.
    To compact all database-group nodes, the command must be sent to each node separately.

  • Target node:
    By default, the operation will be executed on the server node that is defined by the client configuration.
    The operation can be executed on a specific node by using the ForNode method.

  • Target database:
    The database to compact is specified in CompactSettings (see examples below).
    An exception is thrown if the specified database doesn't exist on the server node.

  • In this page:


Examples

Compact documents:

The following example will compact only documents for the specified database.

// Define the compact settings
CompactSettings settings = new CompactSettings
{
    // Database to compact
    DatabaseName = "Northwind",

    // Set 'Documents' to true to compact all documents in database
    // Indexes are not set and will not be compacted
    Documents = true
};

// 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, during compaction the database is offline
operation.WaitForCompletion();
// Define the compact settings
CompactSettings settings = new CompactSettings
{
    // Database to compact
    DatabaseName = "Northwind",

    // Set 'Documents' to true to compact all documents in database
    // Indexes are not set and will not be compacted
    Documents = true
};

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

// Execute compaction by passing the operation to Maintenance.Server.SendAsync
Operation operation = await documentStore.Maintenance.Server.SendAsync(compactOp);

// Wait for operation to complete, during compaction the database is offline
await operation.WaitForCompletionAsync().ConfigureAwait(false);

Compact specific indexes:

The following example will compact only specific indexes.

// 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();
// 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.SendAsync
Operation operation = await documentStore.Maintenance.Server.SendAsync(compactOp);
// Wait for operation to complete
await operation.WaitForCompletionAsync().ConfigureAwait(false);

Compact all indexes:

The following example will compact all indexes and documents.

// 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();
// 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.SendAsync
Operation operation = await documentStore.Maintenance.Server.SendAsync(compactOp);
// Wait for operation to complete
await operation.WaitForCompletionAsync();

Compact on other nodes:

  • By default, an operation executes on the server node that is defined by the client configuration.
  • The following example will compact the database on all member nodes from its database-group topology.
    ForNode is used to execute the operation on a specific node.

// 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();
}
// 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 = await documentStore.Maintenance.Server.ForNode(nodeTag).SendAsync(compactOp);
    // Wait for operation to complete
    await operation.WaitForCompletionAsync();
}

Compaction triggers compression

  • When document compression is turned on, compression is applied to the documents when:

    • New documents that are created and saved.
    • Existing documents that are modified and saved.
  • You can use the compaction operation to compress existing documents without having to modify and save them.
    Executing compaction triggers compression on ALL existing documents for the collections that are configured for compression.

  • Learn more about Compression -vs- Compaction here.

Compact from Studio

  • Compaction can be triggered from the Storage Report view in the Studio.
    The operation will compact the database only on the node being viewed (node info is in the Studio footer).

  • To compact the database on another node,
    simply trigger compaction from the Storage Report view in a browser tab opened for that other node.

Syntax

public CompactDatabaseOperation(CompactSettings compactSettings)
Parameters Type Description
compactSettings CompactSettings Settings for the compact operation
CompactSettings Type Description
DatabaseName string Name of database to compact. Mandatory param.
Documents bool Indicates if documents should be compacted. Optional param.
Indexes string[] List of index names to compact. Optional param.
SkipOptimizeIndexes bool true - Skip Lucene's index optimization while compacting
false - Lucene's index optimization will take place while compacting
Note: Either Documents or Indexes (or both) must be specified