Class Checkpoint

Namespace

RocksDbNet

Assembly

RocksDb.Net.dll

Creates on-disk checkpoints (hard-link-based snapshots) of a RocksDb database. Maps to rocksdb_checkpoint_t.

public sealed class Checkpoint : RocksDbHandle, IDisposable

Inheritance

object

RocksDbHandle

Checkpoint

Implements

IDisposable

Inherited Members

RocksDbHandle.Handle

RocksDbHandle.Owned

RocksDbHandle.IsDisposed

RocksDbHandle.ThrowIfDisposed()

RocksDbHandle.Dispose()

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Methods

Create(RocksDb)

Creates a Checkpoint object for the given database.

public static Checkpoint Create(RocksDb db)

Parameters

db RocksDb

Returns

Checkpoint

CreateCheckpoint(string, ulong)

Creates a new database checkpoint at checkpointDir. If logSizeForFlush is 0, all memtables are flushed.

public void CreateCheckpoint(string checkpointDir, ulong logSizeForFlush = 0)

Parameters

checkpointDir string

logSizeForFlush ulong

DisposeHandle()

Releases the native handle. Called during disposal.

protected override void DisposeHandle()

Remarks

Protected rather than public: it destroys the native object without marking this instance disposed or clearing the handle, so calling it from outside and then disposing normally would free the same pointer twice. It was the most Dispose-looking member on the type. Callers want Dispose().

ExportColumnFamily(ColumnFamilyHandle, string)

Writes one column family's live files into exportDir and returns the metadata needed to import them elsewhere.

public ExportImportFilesMetadata ExportColumnFamily(ColumnFamilyHandle cf, string exportDir)

Parameters

cf ColumnFamilyHandle

The column family to export.

exportDir string

Directory to write into. It must not already exist: RocksDb creates it and fails with "Specified export_dir exists" otherwise, even if the directory is empty. Pass a path under a directory you control rather than one you have already created.

Returns

ExportImportFilesMetadata

Remarks

Unlike CreateCheckpoint(string, ulong), which copies a whole database into something you open separately, this exports a single column family so it can be imported into a database that is already running. That is the way to copy a column family between databases, rename one, or restore just one part of a database.

The export holds no write-ahead log and no history, only the current contents. Dispose the returned metadata when finished with it.