DBOptions

java.lang.Object
- org.rocksdb.RocksObject
- - org.rocksdb.DBOptions

All Implemented Interfaces:

DBOptionsInterface
```
public class DBOptions
extends RocksObject
implements DBOptionsInterface
```
DBOptions to control the behavior of a database. It will be used during the creation of a RocksDB (i.e., RocksDB.open()). If RocksObject.dispose() function is not called, then it will be GC'd automatically and native resources will be released as part of the process.

Field Summary
- Fields inherited from class org.rocksdb.RocksObject
  nativeHandle_

Constructor Summary

Constructors
Constructor and Description

DBOptions()
Construct DBOptions.

Constructors
Constructor and Description
`DBOptions()` Construct DBOptions.

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`adviseRandomOnOpen()` If set true, will hint the underlying file system that the file access pattern is random, when a sst file is opened.
`boolean`	`allowMmapReads()` Allow the OS to mmap file for reading sst tables.
`boolean`	`allowMmapWrites()` Allow the OS to mmap file for writing.
`boolean`	`allowOsBuffer()` Data being read from file storage may be buffered in the OS Default: true
`long`	`bytesPerSync()` Allows OS to incrementally sync files to disk while they are being written, asynchronously, in the background.
`boolean`	`createIfMissing()` Return true if the create_if_missing flag is set to true.
`boolean`	`createMissingColumnFamilies()` Return true if the create_missing_column_families flag is set to true.
`DBOptions`	`createStatistics()` Creates statistics object which collects metrics about database operations.
`java.lang.String`	`dbLogDir()` Returns the directory of info log.
`long`	`deleteObsoleteFilesPeriodMicros()` The periodicity when obsolete files get deleted.
`boolean`	`disableDataSync()` If true, then the contents of data files are not synced to stable storage.
`protected void`	`disposeInternal()` Release the memory allocated for the current instance in the c++ side.
`boolean`	`errorIfExists()` If true, an error will be thrown during RocksDB.open() if the database already exists.
`static DBOptions`	`getDBOptionsFromProps(java.util.Properties properties)` Method to get a options instance by using pre-configured property values.
`InfoLogLevel`	`infoLogLevel()` Returns currently set log level.
`boolean`	`isFdCloseOnExec()` Disable child process inherit open files.
`long`	`keepLogFileNum()` Returns the maximum number of info log files to be kept.
`long`	`logFileTimeToRoll()` Returns the time interval for the info log file to roll (in seconds).
`long`	`manifestPreallocationSize()` Number of bytes to preallocate (via fallocate) the manifest files.
`int`	`maxBackgroundCompactions()` Returns the maximum number of concurrent background compaction jobs, submitted to the default LOW priority thread pool.
`int`	`maxBackgroundFlushes()` Returns the maximum number of concurrent background flush jobs.
`long`	`maxLogFileSize()` Returns the maximum size of a info log file.
`long`	`maxManifestFileSize()` Manifest file is rolled over on reaching this limit.
`int`	`maxOpenFiles()` Number of open files that can be used by the DB.
`long`	`maxTotalWalSize()` Returns the max total wal size.
`boolean`	`paranoidChecks()` If true, the implementation will do aggressive checking of the data it is processing and will stop early if it detects any errors.
`DBOptions`	`setAdviseRandomOnOpen(boolean adviseRandomOnOpen)` If set true, will hint the underlying file system that the file access pattern is random, when a sst file is opened.
`DBOptions`	`setAllowMmapReads(boolean allowMmapReads)` Allow the OS to mmap file for reading sst tables.
`DBOptions`	`setAllowMmapWrites(boolean allowMmapWrites)` Allow the OS to mmap file for writing.
`DBOptions`	`setAllowOsBuffer(boolean allowOsBuffer)` Data being read from file storage may be buffered in the OS Default: true
`DBOptions`	`setBytesPerSync(long bytesPerSync)` Allows OS to incrementally sync files to disk while they are being written, asynchronously, in the background.
`DBOptions`	`setCreateIfMissing(boolean flag)` If this value is set to true, then the database will be created if it is missing during `RocksDB.open()`.
`DBOptions`	`setCreateMissingColumnFamilies(boolean flag)` If true, missing column families will be automatically created
`DBOptions`	`setDbLogDir(java.lang.String dbLogDir)` This specifies the info LOG dir.
`DBOptions`	`setDeleteObsoleteFilesPeriodMicros(long micros)` The periodicity when obsolete files get deleted.
`DBOptions`	`setDisableDataSync(boolean disableDataSync)` If true, then the contents of manifest and data files are not synced to stable storage.
`DBOptions`	`setErrorIfExists(boolean errorIfExists)` If true, an error will be thrown during RocksDB.open() if the database already exists.
`DBOptions`	`setIncreaseParallelism(int totalThreads)` By default, RocksDB uses only one background thread for flush and compaction.
`DBOptions`	`setInfoLogLevel(InfoLogLevel infoLogLevel)` Sets the RocksDB log level.
`DBOptions`	`setIsFdCloseOnExec(boolean isFdCloseOnExec)` Disable child process inherit open files.
`DBOptions`	`setKeepLogFileNum(long keepLogFileNum)` Specifies the maximum number of info log files to be kept.
`DBOptions`	`setLogFileTimeToRoll(long logFileTimeToRoll)` Specifies the time interval for the info log file to roll (in seconds).
`DBOptions`	`setLogger(Logger logger)` Any internal progress/error information generated by the db will be written to the Logger if it is non-nullptr, or to a file stored in the same directory as the DB contents if info_log is nullptr.
`DBOptions`	`setManifestPreallocationSize(long size)` Number of bytes to preallocate (via fallocate) the manifest files.
`DBOptions`	`setMaxBackgroundCompactions(int maxBackgroundCompactions)` Specifies the maximum number of concurrent background compaction jobs, submitted to the default LOW priority thread pool.
`DBOptions`	`setMaxBackgroundFlushes(int maxBackgroundFlushes)` Specifies the maximum number of concurrent background flush jobs.
`DBOptions`	`setMaxLogFileSize(long maxLogFileSize)` Specifies the maximum size of a info log file.
`DBOptions`	`setMaxManifestFileSize(long maxManifestFileSize)` Manifest file is rolled over on reaching this limit.
`DBOptions`	`setMaxOpenFiles(int maxOpenFiles)` Number of open files that can be used by the DB.
`DBOptions`	`setMaxTotalWalSize(long maxTotalWalSize)` Once write-ahead logs exceed this size, we will start forcing the flush of column families whose memtables are backed by the oldest live WAL file (i.e.
`DBOptions`	`setParanoidChecks(boolean paranoidChecks)` If true, the implementation will do aggressive checking of the data it is processing and will stop early if it detects any errors.
`DBOptions`	`setRateLimiterConfig(RateLimiterConfig config)` Use to control write rate of flush and compaction.
`DBOptions`	`setSkipLogErrorOnRecovery(boolean skip)` Deprecated.
`DBOptions`	`setStatsDumpPeriodSec(int statsDumpPeriodSec)` if not zero, dump rocksdb.stats to LOG every stats_dump_period_sec Default: 3600 (1 hour)
`DBOptions`	`setTableCacheNumshardbits(int tableCacheNumshardbits)` Number of shards used for table cache.
`DBOptions`	`setTableCacheRemoveScanCountLimit(int limit)` During data eviction of table's LRU cache, it would be inefficient to strictly follow LRU because this piece of memory will not really be released unless its refcount falls to zero.
`DBOptions`	`setUseAdaptiveMutex(boolean useAdaptiveMutex)` Use adaptive mutex, which spins in the user space before resorting to kernel.
`DBOptions`	`setUseFsync(boolean useFsync)` If true, then every store to stable storage will issue a fsync.
`DBOptions`	`setWalDir(java.lang.String walDir)` This specifies the absolute dir path for write-ahead logs (WAL).
`DBOptions`	`setWalSizeLimitMB(long sizeLimitMB)` WalTtlSeconds() and walSizeLimitMB() affect how archived logs will be deleted.
`DBOptions`	`setWalTtlSeconds(long walTtlSeconds)` `DBOptionsInterface.walTtlSeconds()` and `DBOptionsInterface.walSizeLimitMB()` affect how archived logs will be deleted.
`boolean`	`skipLogErrorOnRecovery()` Deprecated.
`Statistics`	`statisticsPtr()` Returns statistics object.
`int`	`statsDumpPeriodSec()` If not zero, dump rocksdb.stats to LOG every stats_dump_period_sec Default: 3600 (1 hour)
`int`	`tableCacheNumshardbits()` Number of shards used for table cache.
`int`	`tableCacheRemoveScanCountLimit()` During data eviction of table's LRU cache, it would be inefficient to strictly follow LRU because this piece of memory will not really be released unless its refcount falls to zero.
`boolean`	`useAdaptiveMutex()` Use adaptive mutex, which spins in the user space before resorting to kernel.
`boolean`	`useFsync()` If true, then every store to stable storage will issue a fsync.
`java.lang.String`	`walDir()` Returns the path to the write-ahead-logs (WAL) directory.
`long`	`walSizeLimitMB()` `DBOptionsInterface.walTtlSeconds()` and `#walSizeLimitMB()` affect how archived logs will be deleted.
`long`	`walTtlSeconds()` WalTtlSeconds() and walSizeLimitMB() affect how archived logs will be deleted.

Methods inherited from class org.rocksdb.RocksObject
disOwnNativeHandle, dispose, finalize, isInitialized, isOwningNativeHandle

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - DBOptions
```
public DBOptions()
```
    Construct DBOptions. This constructor will create (by allocating a block of memory) an rocksdb::DBOptions in the c++ side.
- Method Detail
  - getDBOptionsFromProps
```
public static DBOptions getDBOptionsFromProps(java.util.Properties properties)
```
    Method to get a options instance by using pre-configured property values. If one or many values are undefined in the context of RocksDB the method will return a null value.
    
    Note: Property keys can be derived from getter methods within the options class. Example: the method allowMmapReads() has a property key: allow_mmap_reads.
    
    Parameters:
    properties - Properties instance.
    
    Returns:
    instance or null.
    
    Throws:
    
    java.lang.IllegalArgumentException - if null or empty Properties instance is passed to the method call.
  - setIncreaseParallelism
```
public DBOptions setIncreaseParallelism(int totalThreads)
```
    Description copied from interface: DBOptionsInterface
    
    By default, RocksDB uses only one background thread for flush and compaction. Calling this function will set it up such that total of `total_threads` is used.
    
    You almost definitely want to call this function if your system is bottlenecked by RocksDB.
    
    Specified by:
    
    setIncreaseParallelism in interface DBOptionsInterface
    
    Parameters:
    totalThreads - The total number of threads to be used by RocksDB. A good value is the number of cores.
    
    Returns:
    the instance of the current Options
  - setCreateIfMissing
```
public DBOptions setCreateIfMissing(boolean flag)
```
    Description copied from interface: DBOptionsInterface
    
    If this value is set to true, then the database will be created if it is missing during RocksDB.open(). Default: false
    
    Specified by:
    
    setCreateIfMissing in interface DBOptionsInterface
    
    Parameters:
    flag - a flag indicating whether to create a database the specified database in RocksDB.open(org.rocksdb.Options, String) operation is missing.
    
    Returns:
    the instance of the current Options
    See Also:
    RocksDB.open(org.rocksdb.Options, String)
  - createIfMissing
```
public boolean createIfMissing()
```
    Description copied from interface: DBOptionsInterface
    
    Return true if the create_if_missing flag is set to true. If true, the database will be created if it is missing.
    
    Specified by:
    
    createIfMissing in interface DBOptionsInterface
    
    Returns:
    true if the createIfMissing option is set to true.
    See Also:
    DBOptionsInterface.setCreateIfMissing(boolean)
  - setCreateMissingColumnFamilies
```
public DBOptions setCreateMissingColumnFamilies(boolean flag)
```
    Description copied from interface: DBOptionsInterface
    
    If true, missing column families will be automatically created
    
    Default: false
    
    Specified by:
    
    setCreateMissingColumnFamilies in interface DBOptionsInterface
    
    Parameters:
    flag - a flag indicating if missing column families shall be created automatically.
    
    Returns:
    true if missing column families shall be created automatically on open.
  - createMissingColumnFamilies
```
public boolean createMissingColumnFamilies()
```
    Description copied from interface: DBOptionsInterface
    
    Return true if the create_missing_column_families flag is set to true. If true column families be created if missing.
    
    Specified by:
    
    createMissingColumnFamilies in interface DBOptionsInterface
    
    Returns:
    true if the createMissingColumnFamilies is set to true.
    See Also:
    DBOptionsInterface.setCreateMissingColumnFamilies(boolean)
  - setErrorIfExists
```
public DBOptions setErrorIfExists(boolean errorIfExists)
```
    Description copied from interface: DBOptionsInterface
    
    If true, an error will be thrown during RocksDB.open() if the database already exists. Default: false
    
    Specified by:
    
    setErrorIfExists in interface DBOptionsInterface
    
    Parameters:
    errorIfExists - if true, an exception will be thrown during RocksDB.open() if the database already exists.
    
    Returns:
    the reference to the current option.
    See Also:
    RocksDB.open(org.rocksdb.Options, String)
  - errorIfExists
```
public boolean errorIfExists()
```
    Description copied from interface: DBOptionsInterface
    
    If true, an error will be thrown during RocksDB.open() if the database already exists.
    
    Specified by:
    
    errorIfExists in interface DBOptionsInterface
    
    Returns:
    if true, an error is raised when the specified database already exists before open.
  - setParanoidChecks
```
public DBOptions setParanoidChecks(boolean paranoidChecks)
```
    Description copied from interface: DBOptionsInterface
    
    If true, the implementation will do aggressive checking of the data it is processing and will stop early if it detects any errors. This may have unforeseen ramifications: for example, a corruption of one DB entry may cause a large number of entries to become unreadable or for the entire DB to become unopenable. If any of the writes to the database fails (Put, Delete, Merge, Write), the database will switch to read-only mode and fail all other Write operations. Default: true
    
    Specified by:
    
    setParanoidChecks in interface DBOptionsInterface
    
    Parameters:
    paranoidChecks - a flag to indicate whether paranoid-check is on.
    
    Returns:
    the reference to the current option.
  - paranoidChecks
```
public boolean paranoidChecks()
```
    Description copied from interface: DBOptionsInterface
    
    If true, the implementation will do aggressive checking of the data it is processing and will stop early if it detects any errors. This may have unforeseen ramifications: for example, a corruption of one DB entry may cause a large number of entries to become unreadable or for the entire DB to become unopenable. If any of the writes to the database fails (Put, Delete, Merge, Write), the database will switch to read-only mode and fail all other Write operations.
    
    Specified by:
    
    paranoidChecks in interface DBOptionsInterface
    
    Returns:
    a boolean indicating whether paranoid-check is on.
  - setRateLimiterConfig
```
public DBOptions setRateLimiterConfig(RateLimiterConfig config)
```
    Description copied from interface: DBOptionsInterface
    
    Use to control write rate of flush and compaction. Flush has higher priority than compaction. Rate limiting is disabled if nullptr. Default: nullptr
    
    Specified by:
    
    setRateLimiterConfig in interface DBOptionsInterface
    
    Parameters:
    config - rate limiter config.
    
    Returns:
    the instance of the current Object.
  - setLogger
```
public DBOptions setLogger(Logger logger)
```
    Description copied from interface: DBOptionsInterface
    
    Any internal progress/error information generated by the db will be written to the Logger if it is non-nullptr, or to a file stored in the same directory as the DB contents if info_log is nullptr.
    
    Default: nullptr
    
    Specified by:
    
    setLogger in interface DBOptionsInterface
    
    Parameters:
    logger - Logger instance.
    
    Returns:
    the instance of the current Object.
  - setInfoLogLevel
```
public DBOptions setInfoLogLevel(InfoLogLevel infoLogLevel)
```
    Description copied from interface: DBOptionsInterface
    
    Sets the RocksDB log level. Default level is INFO
    
    Specified by:
    
    setInfoLogLevel in interface DBOptionsInterface
    
    Parameters:
    infoLogLevel - log level to set.
    
    Returns:
    the instance of the current Object.
  - infoLogLevel
```
public InfoLogLevel infoLogLevel()
```
    Description copied from interface: DBOptionsInterface
    
    Returns currently set log level.
    
    Specified by:
    
    infoLogLevel in interface DBOptionsInterface
    
    Returns:
    InfoLogLevel instance.
  - setMaxOpenFiles
```
public DBOptions setMaxOpenFiles(int maxOpenFiles)
```
    Description copied from interface: DBOptionsInterface
    
    Number of open files that can be used by the DB. You may need to increase this if your database has a large working set. Value -1 means files opened are always kept open. You can estimate number of files based on target_file_size_base and target_file_size_multiplier for level-based compaction. For universal-style compaction, you can usually set it to -1. Default: 5000
    
    Specified by:
    
    setMaxOpenFiles in interface DBOptionsInterface
    
    Parameters:
    maxOpenFiles - the maximum number of open files.
    
    Returns:
    the instance of the current Object.
  - maxOpenFiles
```
public int maxOpenFiles()
```
    Description copied from interface: DBOptionsInterface
    
    Number of open files that can be used by the DB. You may need to increase this if your database has a large working set. Value -1 means files opened are always kept open. You can estimate number of files based on target_file_size_base and target_file_size_multiplier for level-based compaction. For universal-style compaction, you can usually set it to -1.
    
    Specified by:
    
    maxOpenFiles in interface DBOptionsInterface
    
    Returns:
    the maximum number of open files.
  - setMaxTotalWalSize
```
public DBOptions setMaxTotalWalSize(long maxTotalWalSize)
```
    Description copied from interface: DBOptionsInterface
    
    Once write-ahead logs exceed this size, we will start forcing the flush of column families whose memtables are backed by the oldest live WAL file (i.e. the ones that are causing all the space amplification).
    
    If set to 0 (default), we will dynamically choose the WAL size limit to be [sum of all write_buffer_size * max_write_buffer_number] * 2
    
    Default: 0
    
    Specified by:
    
    setMaxTotalWalSize in interface DBOptionsInterface
    
    Parameters:
    maxTotalWalSize - max total wal size.
    
    Returns:
    the instance of the current Object.
  - maxTotalWalSize
```
public long maxTotalWalSize()
```
    Description copied from interface: DBOptionsInterface
    
    Returns the max total wal size. Once write-ahead logs exceed this size, we will start forcing the flush of column families whose memtables are backed by the oldest live WAL file (i.e. the ones that are causing all the space amplification).
    
    If set to 0 (default), we will dynamically choose the WAL size limit to be [sum of all write_buffer_size * max_write_buffer_number] * 2
    
    Specified by:
    
    maxTotalWalSize in interface DBOptionsInterface
    
    Returns:
    max total wal size
  - createStatistics
```
public DBOptions createStatistics()
```
    Description copied from interface: DBOptionsInterface
    
    Creates statistics object which collects metrics about database operations. Statistics objects should not be shared between DB instances as it does not use any locks to prevent concurrent updates.
    
    Specified by:
    
    createStatistics in interface DBOptionsInterface
    
    Returns:
    the instance of the current Object.
    See Also:
    RocksDB.open(org.rocksdb.Options, String)
  - statisticsPtr
```
public Statistics statisticsPtr()
```
    Description copied from interface: DBOptionsInterface
    
    Returns statistics object. Calls DBOptionsInterface.createStatistics() if C++ returns nullptr for statistics.
    
    Specified by:
    
    statisticsPtr in interface DBOptionsInterface
    
    Returns:
    the instance of the statistics object.
    See Also:
    DBOptionsInterface.createStatistics()
  - setDisableDataSync
```
public DBOptions setDisableDataSync(boolean disableDataSync)
```
    Description copied from interface: DBOptionsInterface
    
    If true, then the contents of manifest and data files are not synced to stable storage. Their contents remain in the OS buffers till theOS decides to flush them.
    
    This option is good for bulk-loading of data.
    
    Once the bulk-loading is complete, please issue a sync to the OS to flush all dirty buffers to stable storage.
    
    Default: false
    
    Specified by:
    
    setDisableDataSync in interface DBOptionsInterface
    
    Parameters:
    disableDataSync - a boolean flag to specify whether to disable data sync.
    
    Returns:
    the instance of the current Object.
  - disableDataSync
```
public boolean disableDataSync()
```
    Description copied from interface: DBOptionsInterface
    
    If true, then the contents of data files are not synced to stable storage. Their contents remain in the OS buffers till the OS decides to flush them. This option is good for bulk-loading of data. Once the bulk-loading is complete, please issue a sync to the OS to flush all dirty buffers to stable storage.
    
    Specified by:
    
    disableDataSync in interface DBOptionsInterface
    
    Returns:
    if true, then data-sync is disabled.
  - setUseFsync
```
public DBOptions setUseFsync(boolean useFsync)
```
    Description copied from interface: DBOptionsInterface
    
    If true, then every store to stable storage will issue a fsync.
    
    If false, then every store to stable storage will issue a fdatasync. This parameter should be set to true while storing data to filesystem like ext3 that can lose files after a reboot.
    
    Default: false
    
    Specified by:
    
    setUseFsync in interface DBOptionsInterface
    
    Parameters:
    useFsync - a boolean flag to specify whether to use fsync
    
    Returns:
    the instance of the current Object.
  - useFsync
```
public boolean useFsync()
```
    Description copied from interface: DBOptionsInterface
    
    If true, then every store to stable storage will issue a fsync.
    
    If false, then every store to stable storage will issue a fdatasync. This parameter should be set to true while storing data to filesystem like ext3 that can lose files after a reboot.
    
    Specified by:
    
    useFsync in interface DBOptionsInterface
    
    Returns:
    boolean value indicating if fsync is used.
  - setDbLogDir
```
public DBOptions setDbLogDir(java.lang.String dbLogDir)
```
    Description copied from interface: DBOptionsInterface
    
    This specifies the info LOG dir. If it is empty, the log files will be in the same dir as data. If it is non empty, the log files will be in the specified dir, and the db data dir's absolute path will be used as the log file name's prefix.
    
    Specified by:
    
    setDbLogDir in interface DBOptionsInterface
    
    Parameters:
    dbLogDir - the path to the info log directory
    
    Returns:
    the instance of the current Object.
  - dbLogDir
```
public java.lang.String dbLogDir()
```
    Description copied from interface: DBOptionsInterface
    
    Returns the directory of info log. If it is empty, the log files will be in the same dir as data. If it is non empty, the log files will be in the specified dir, and the db data dir's absolute path will be used as the log file name's prefix.
    
    Specified by:
    
    dbLogDir in interface DBOptionsInterface
    
    Returns:
    the path to the info log directory
  - setWalDir
```
public DBOptions setWalDir(java.lang.String walDir)
```
    Description copied from interface: DBOptionsInterface
    
    This specifies the absolute dir path for write-ahead logs (WAL). If it is empty, the log files will be in the same dir as data, dbname is used as the data dir by default If it is non empty, the log files will be in kept the specified dir. When destroying the db, all log files in wal_dir and the dir itself is deleted
    
    Specified by:
    
    setWalDir in interface DBOptionsInterface
    
    Parameters:
    walDir - the path to the write-ahead-log directory.
    
    Returns:
    the instance of the current Object.
  - walDir
```
public java.lang.String walDir()
```
    Description copied from interface: DBOptionsInterface
    
    Returns the path to the write-ahead-logs (WAL) directory. If it is empty, the log files will be in the same dir as data, dbname is used as the data dir by default If it is non empty, the log files will be in kept the specified dir. When destroying the db, all log files in wal_dir and the dir itself is deleted
    
    Specified by:
    
    walDir in interface DBOptionsInterface
    
    Returns:
    the path to the write-ahead-logs (WAL) directory.
  - setDeleteObsoleteFilesPeriodMicros
```
public DBOptions setDeleteObsoleteFilesPeriodMicros(long micros)
```
    Description copied from interface: DBOptionsInterface
    
    The periodicity when obsolete files get deleted. The default value is 6 hours. The files that get out of scope by compaction process will still get automatically delete on every compaction, regardless of this setting
    
    Specified by:
    
    setDeleteObsoleteFilesPeriodMicros in interface DBOptionsInterface
    
    Parameters:
    micros - the time interval in micros
    
    Returns:
    the instance of the current Object.
  - deleteObsoleteFilesPeriodMicros
```
public long deleteObsoleteFilesPeriodMicros()
```
    Description copied from interface: DBOptionsInterface
    
    The periodicity when obsolete files get deleted. The default value is 6 hours. The files that get out of scope by compaction process will still get automatically delete on every compaction, regardless of this setting
    
    Specified by:
    
    deleteObsoleteFilesPeriodMicros in interface DBOptionsInterface
    
    Returns:
    the time interval in micros when obsolete files will be deleted.
  - setMaxBackgroundCompactions
```
public DBOptions setMaxBackgroundCompactions(int maxBackgroundCompactions)
```
    Description copied from interface: DBOptionsInterface
    
    Specifies the maximum number of concurrent background compaction jobs, submitted to the default LOW priority thread pool. If you're increasing this, also consider increasing number of threads in LOW priority thread pool. For more information, see Default: 1
    
    Specified by:
    
    setMaxBackgroundCompactions in interface DBOptionsInterface
    
    Parameters:
    maxBackgroundCompactions - the maximum number of background compaction jobs.
    
    Returns:
    the instance of the current Object.
    See Also:
    Env.setBackgroundThreads(int), Env.setBackgroundThreads(int, int), DBOptionsInterface.maxBackgroundFlushes()
  - maxBackgroundCompactions
```
public int maxBackgroundCompactions()
```
    Description copied from interface: DBOptionsInterface
    
    Returns the maximum number of concurrent background compaction jobs, submitted to the default LOW priority thread pool. When increasing this number, we may also want to consider increasing number of threads in LOW priority thread pool. Default: 1
    
    Specified by:
    
    maxBackgroundCompactions in interface DBOptionsInterface
    
    Returns:
    the maximum number of concurrent background compaction jobs.
    See Also:
    Env.setBackgroundThreads(int), Env.setBackgroundThreads(int, int)
  - setMaxBackgroundFlushes
```
public DBOptions setMaxBackgroundFlushes(int maxBackgroundFlushes)
```
    Description copied from interface: DBOptionsInterface
    
    Specifies the maximum number of concurrent background flush jobs. If you're increasing this, also consider increasing number of threads in HIGH priority thread pool. For more information, see Default: 1
    
    Specified by:
    
    setMaxBackgroundFlushes in interface DBOptionsInterface
    
    Parameters:
    maxBackgroundFlushes - number of max concurrent flush jobs
    
    Returns:
    the instance of the current Object.
    See Also:
    Env.setBackgroundThreads(int), Env.setBackgroundThreads(int, int), DBOptionsInterface.maxBackgroundCompactions()
  - maxBackgroundFlushes
```
public int maxBackgroundFlushes()
```
    Description copied from interface: DBOptionsInterface
    
    Returns the maximum number of concurrent background flush jobs. If you're increasing this, also consider increasing number of threads in HIGH priority thread pool. For more information, see Default: 1
    
    Specified by:
    
    maxBackgroundFlushes in interface DBOptionsInterface
    
    Returns:
    the maximum number of concurrent background flush jobs.
    See Also:
    Env.setBackgroundThreads(int), Env.setBackgroundThreads(int, int)
  - setMaxLogFileSize
```
public DBOptions setMaxLogFileSize(long maxLogFileSize)
```
    Description copied from interface: DBOptionsInterface
    
    Specifies the maximum size of a info log file. If the current log file is larger than `max_log_file_size`, a new info log file will be created. If 0, all logs will be written to one log file.
    
    Specified by:
    
    setMaxLogFileSize in interface DBOptionsInterface
    
    Parameters:
    maxLogFileSize - the maximum size of a info log file.
    
    Returns:
    the instance of the current Object.
  - maxLogFileSize
```
public long maxLogFileSize()
```
    Description copied from interface: DBOptionsInterface
    
    Returns the maximum size of a info log file. If the current log file is larger than this size, a new info log file will be created. If 0, all logs will be written to one log file.
    
    Specified by:
    
    maxLogFileSize in interface DBOptionsInterface
    
    Returns:
    the maximum size of the info log file.
  - setLogFileTimeToRoll
```
public DBOptions setLogFileTimeToRoll(long logFileTimeToRoll)
```
    Description copied from interface: DBOptionsInterface
    
    Specifies the time interval for the info log file to roll (in seconds). If specified with non-zero value, log file will be rolled if it has been active longer than `log_file_time_to_roll`. Default: 0 (disabled)
    
    Specified by:
    
    setLogFileTimeToRoll in interface DBOptionsInterface
    
    Parameters:
    logFileTimeToRoll - the time interval in seconds.
    
    Returns:
    the instance of the current Object.
  - logFileTimeToRoll
```
public long logFileTimeToRoll()
```
    Description copied from interface: DBOptionsInterface
    
    Returns the time interval for the info log file to roll (in seconds). If specified with non-zero value, log file will be rolled if it has been active longer than `log_file_time_to_roll`. Default: 0 (disabled)
    
    Specified by:
    
    logFileTimeToRoll in interface DBOptionsInterface
    
    Returns:
    the time interval in seconds.
  - setKeepLogFileNum
```
public DBOptions setKeepLogFileNum(long keepLogFileNum)
```
    Description copied from interface: DBOptionsInterface
    
    Specifies the maximum number of info log files to be kept. Default: 1000
    
    Specified by:
    
    setKeepLogFileNum in interface DBOptionsInterface
    
    Parameters:
    keepLogFileNum - the maximum number of info log files to be kept.
    
    Returns:
    the instance of the current Object.
  - keepLogFileNum
```
public long keepLogFileNum()
```
    Description copied from interface: DBOptionsInterface
    
    Returns the maximum number of info log files to be kept. Default: 1000
    
    Specified by:
    
    keepLogFileNum in interface DBOptionsInterface
    
    Returns:
    the maximum number of info log files to be kept.
  - setMaxManifestFileSize
```
public DBOptions setMaxManifestFileSize(long maxManifestFileSize)
```
    Description copied from interface: DBOptionsInterface
    
    Manifest file is rolled over on reaching this limit. The older manifest file be deleted. The default value is MAX_INT so that roll-over does not take place.
    
    Specified by:
    
    setMaxManifestFileSize in interface DBOptionsInterface
    
    Parameters:
    maxManifestFileSize - the size limit of a manifest file.
    
    Returns:
    the instance of the current Object.
  - maxManifestFileSize
```
public long maxManifestFileSize()
```
    Description copied from interface: DBOptionsInterface
    
    Manifest file is rolled over on reaching this limit. The older manifest file be deleted. The default value is MAX_INT so that roll-over does not take place.
    
    Specified by:
    
    maxManifestFileSize in interface DBOptionsInterface
    
    Returns:
    the size limit of a manifest file.
  - setTableCacheNumshardbits
```
public DBOptions setTableCacheNumshardbits(int tableCacheNumshardbits)
```
    Description copied from interface: DBOptionsInterface
    
    Number of shards used for table cache.
    
    Specified by:
    
    setTableCacheNumshardbits in interface DBOptionsInterface
    
    Parameters:
    tableCacheNumshardbits - the number of chards
    
    Returns:
    the instance of the current Object.
  - tableCacheNumshardbits
```
public int tableCacheNumshardbits()
```
    Description copied from interface: DBOptionsInterface
    
    Number of shards used for table cache.
    
    Specified by:
    
    tableCacheNumshardbits in interface DBOptionsInterface
    
    Returns:
    the number of shards used for table cache.
  - setTableCacheRemoveScanCountLimit
```
public DBOptions setTableCacheRemoveScanCountLimit(int limit)
```
    Description copied from interface: DBOptionsInterface
    
    During data eviction of table's LRU cache, it would be inefficient to strictly follow LRU because this piece of memory will not really be released unless its refcount falls to zero. Instead, make two passes: the first pass will release items with refcount = 1, and if not enough space releases after scanning the number of elements specified by this parameter, we will remove items in LRU order.
    
    Specified by:
    
    setTableCacheRemoveScanCountLimit in interface DBOptionsInterface
    
    Parameters:
    limit - scan count limit
    
    Returns:
    the instance of the current Object.
  - tableCacheRemoveScanCountLimit
```
public int tableCacheRemoveScanCountLimit()
```
    Description copied from interface: DBOptionsInterface
    
    During data eviction of table's LRU cache, it would be inefficient to strictly follow LRU because this piece of memory will not really be released unless its refcount falls to zero. Instead, make two passes: the first pass will release items with refcount = 1, and if not enough space releases after scanning the number of elements specified by this parameter, we will remove items in LRU order.
    
    Specified by:
    
    tableCacheRemoveScanCountLimit in interface DBOptionsInterface
    
    Returns:
    scan count limit
  - setWalTtlSeconds
```
public DBOptions setWalTtlSeconds(long walTtlSeconds)
```
    Description copied from interface: DBOptionsInterface
    DBOptionsInterface.walTtlSeconds() and DBOptionsInterface.walSizeLimitMB() affect how archived logs will be deleted.
    1. If both set to 0, logs will be deleted asap and will not get into the archive.
    2. If WAL_ttl_seconds is 0 and WAL_size_limit_MB is not 0, WAL files will be checked every 10 min and if total size is greater then WAL_size_limit_MB, they will be deleted starting with the earliest until size_limit is met. All empty files will be deleted.
    3. If WAL_ttl_seconds is not 0 and WAL_size_limit_MB is 0, then WAL files will be checked every WAL_ttl_secondsi / 2 and those that are older than WAL_ttl_seconds will be deleted.
    4. If both are not 0, WAL files will be checked every 10 min and both checks will be performed with ttl being first.
    Specified by:
    
    setWalTtlSeconds in interface DBOptionsInterface
    
    Parameters:
    walTtlSeconds - the ttl seconds
    
    Returns:
    the instance of the current Object.
    See Also:
    DBOptionsInterface.setWalSizeLimitMB(long)
  - walTtlSeconds
```
public long walTtlSeconds()
```
    Description copied from interface: DBOptionsInterface
    WalTtlSeconds() and walSizeLimitMB() affect how archived logs will be deleted.
    1. If both set to 0, logs will be deleted asap and will not get into the archive.
    2. If WAL_ttl_seconds is 0 and WAL_size_limit_MB is not 0, WAL files will be checked every 10 min and if total size is greater then WAL_size_limit_MB, they will be deleted starting with the earliest until size_limit is met. All empty files will be deleted.
    3. If WAL_ttl_seconds is not 0 and WAL_size_limit_MB is 0, then WAL files will be checked every WAL_ttl_secondsi / 2 and those that are older than WAL_ttl_seconds will be deleted.
    4. If both are not 0, WAL files will be checked every 10 min and both checks will be performed with ttl being first.
    Specified by:
    
    walTtlSeconds in interface DBOptionsInterface
    
    Returns:
    the wal-ttl seconds
    See Also:
    DBOptionsInterface.walSizeLimitMB()
  - setWalSizeLimitMB
```
public DBOptions setWalSizeLimitMB(long sizeLimitMB)
```
    Description copied from interface: DBOptionsInterface
    WalTtlSeconds() and walSizeLimitMB() affect how archived logs will be deleted.
    1. If both set to 0, logs will be deleted asap and will not get into the archive.
    2. If WAL_ttl_seconds is 0 and WAL_size_limit_MB is not 0, WAL files will be checked every 10 min and if total size is greater then WAL_size_limit_MB, they will be deleted starting with the earliest until size_limit is met. All empty files will be deleted.
    3. If WAL_ttl_seconds is not 0 and WAL_size_limit_MB is 0, then WAL files will be checked every WAL_ttl_secondsi / 2 and those that are older than WAL_ttl_seconds will be deleted.
    4. If both are not 0, WAL files will be checked every 10 min and both checks will be performed with ttl being first.
    Specified by:
    
    setWalSizeLimitMB in interface DBOptionsInterface
    
    Parameters:
    sizeLimitMB - size limit in mega-bytes.
    
    Returns:
    the instance of the current Object.
    See Also:
    DBOptionsInterface.setWalSizeLimitMB(long)
  - walSizeLimitMB
```
public long walSizeLimitMB()
```
    Description copied from interface: DBOptionsInterface
    DBOptionsInterface.walTtlSeconds() and #walSizeLimitMB() affect how archived logs will be deleted.
    1. If both set to 0, logs will be deleted asap and will not get into the archive.
    2. If WAL_ttl_seconds is 0 and WAL_size_limit_MB is not 0, WAL files will be checked every 10 min and if total size is greater then WAL_size_limit_MB, they will be deleted starting with the earliest until size_limit is met. All empty files will be deleted.
    3. If WAL_ttl_seconds is not 0 and WAL_size_limit_MB is 0, then WAL files will be checked every WAL_ttl_seconds i / 2 and those that are older than WAL_ttl_seconds will be deleted.
    4. If both are not 0, WAL files will be checked every 10 min and both checks will be performed with ttl being first.
    Specified by:
    
    walSizeLimitMB in interface DBOptionsInterface
    
    Returns:
    size limit in mega-bytes.
    See Also:
    DBOptionsInterface.walSizeLimitMB()
  - setManifestPreallocationSize
```
public DBOptions setManifestPreallocationSize(long size)
```
    Description copied from interface: DBOptionsInterface
    
    Number of bytes to preallocate (via fallocate) the manifest files. Default is 4mb, which is reasonable to reduce random IO as well as prevent overallocation for mounts that preallocate large amounts of data (such as xfs's allocsize option).
    
    Specified by:
    
    setManifestPreallocationSize in interface DBOptionsInterface
    
    Parameters:
    size - the size in byte
    
    Returns:
    the instance of the current Object.
  - manifestPreallocationSize
```
public long manifestPreallocationSize()
```
    Description copied from interface: DBOptionsInterface
    
    Number of bytes to preallocate (via fallocate) the manifest files. Default is 4mb, which is reasonable to reduce random IO as well as prevent overallocation for mounts that preallocate large amounts of data (such as xfs's allocsize option).
    
    Specified by:
    
    manifestPreallocationSize in interface DBOptionsInterface
    
    Returns:
    size in bytes.
  - setAllowOsBuffer
```
public DBOptions setAllowOsBuffer(boolean allowOsBuffer)
```
    Description copied from interface: DBOptionsInterface
    
    Data being read from file storage may be buffered in the OS Default: true
    
    Specified by:
    
    setAllowOsBuffer in interface DBOptionsInterface
    
    Parameters:
    allowOsBuffer - if true, then OS buffering is allowed.
    
    Returns:
    the instance of the current Object.
  - allowOsBuffer
```
public boolean allowOsBuffer()
```
    Description copied from interface: DBOptionsInterface
    
    Data being read from file storage may be buffered in the OS Default: true
    
    Specified by:
    
    allowOsBuffer in interface DBOptionsInterface
    
    Returns:
    if true, then OS buffering is allowed.
  - setAllowMmapReads
```
public DBOptions setAllowMmapReads(boolean allowMmapReads)
```
    Description copied from interface: DBOptionsInterface
    
    Allow the OS to mmap file for reading sst tables. Default: false
    
    Specified by:
    
    setAllowMmapReads in interface DBOptionsInterface
    
    Parameters:
    allowMmapReads - true if mmap reads are allowed.
    
    Returns:
    the instance of the current Object.
  - allowMmapReads
```
public boolean allowMmapReads()
```
    Description copied from interface: DBOptionsInterface
    
    Allow the OS to mmap file for reading sst tables. Default: false
    
    Specified by:
    
    allowMmapReads in interface DBOptionsInterface
    
    Returns:
    true if mmap reads are allowed.
  - setAllowMmapWrites
```
public DBOptions setAllowMmapWrites(boolean allowMmapWrites)
```
    Description copied from interface: DBOptionsInterface
    
    Allow the OS to mmap file for writing. Default: false
    
    Specified by:
    
    setAllowMmapWrites in interface DBOptionsInterface
    
    Parameters:
    allowMmapWrites - true if mmap writes are allowd.
    
    Returns:
    the instance of the current Object.
  - allowMmapWrites
```
public boolean allowMmapWrites()
```
    Description copied from interface: DBOptionsInterface
    
    Allow the OS to mmap file for writing. Default: false
    
    Specified by:
    
    allowMmapWrites in interface DBOptionsInterface
    
    Returns:
    true if mmap writes are allowed.
  - setIsFdCloseOnExec
```
public DBOptions setIsFdCloseOnExec(boolean isFdCloseOnExec)
```
    Description copied from interface: DBOptionsInterface
    
    Disable child process inherit open files. Default: true
    
    Specified by:
    
    setIsFdCloseOnExec in interface DBOptionsInterface
    
    Parameters:
    isFdCloseOnExec - true if child process inheriting open files is disabled.
    
    Returns:
    the instance of the current Object.
  - isFdCloseOnExec
```
public boolean isFdCloseOnExec()
```
    Description copied from interface: DBOptionsInterface
    
    Disable child process inherit open files. Default: true
    
    Specified by:
    
    isFdCloseOnExec in interface DBOptionsInterface
    
    Returns:
    true if child process inheriting open files is disabled.
  - setSkipLogErrorOnRecovery
```
@Deprecated
public DBOptions setSkipLogErrorOnRecovery(boolean skip)
```
    Deprecated.
    
    Description copied from interface: DBOptionsInterface
    
    Skip log corruption error on recovery (If client is ok with losing most recent changes) Default: false
    
    Specified by:
    
    setSkipLogErrorOnRecovery in interface DBOptionsInterface
    
    Parameters:
    skip - true if log corruption errors are skipped during recovery.
    
    Returns:
    the instance of the current Object.
  - skipLogErrorOnRecovery
```
@Deprecated
public boolean skipLogErrorOnRecovery()
```
    Deprecated.
    
    Description copied from interface: DBOptionsInterface
    
    Skip log corruption error on recovery (If client is ok with losing most recent changes) Default: false
    
    Specified by:
    
    skipLogErrorOnRecovery in interface DBOptionsInterface
    
    Returns:
    true if log corruption errors are skipped during recovery.
  - setStatsDumpPeriodSec
```
public DBOptions setStatsDumpPeriodSec(int statsDumpPeriodSec)
```
    Description copied from interface: DBOptionsInterface
    
    if not zero, dump rocksdb.stats to LOG every stats_dump_period_sec Default: 3600 (1 hour)
    
    Specified by:
    
    setStatsDumpPeriodSec in interface DBOptionsInterface
    
    Parameters:
    statsDumpPeriodSec - time interval in seconds.
    
    Returns:
    the instance of the current Object.
  - statsDumpPeriodSec
```
public int statsDumpPeriodSec()
```
    Description copied from interface: DBOptionsInterface
    
    If not zero, dump rocksdb.stats to LOG every stats_dump_period_sec Default: 3600 (1 hour)
    
    Specified by:
    
    statsDumpPeriodSec in interface DBOptionsInterface
    
    Returns:
    time interval in seconds.
  - setAdviseRandomOnOpen
```
public DBOptions setAdviseRandomOnOpen(boolean adviseRandomOnOpen)
```
    Description copied from interface: DBOptionsInterface
    
    If set true, will hint the underlying file system that the file access pattern is random, when a sst file is opened. Default: true
    
    Specified by:
    
    setAdviseRandomOnOpen in interface DBOptionsInterface
    
    Parameters:
    adviseRandomOnOpen - true if hinting random access is on.
    
    Returns:
    the instance of the current Object.
  - adviseRandomOnOpen
```
public boolean adviseRandomOnOpen()
```
    Description copied from interface: DBOptionsInterface
    
    If set true, will hint the underlying file system that the file access pattern is random, when a sst file is opened. Default: true
    
    Specified by:
    
    adviseRandomOnOpen in interface DBOptionsInterface
    
    Returns:
    true if hinting random access is on.
  - setUseAdaptiveMutex
```
public DBOptions setUseAdaptiveMutex(boolean useAdaptiveMutex)
```
    Description copied from interface: DBOptionsInterface
    
    Use adaptive mutex, which spins in the user space before resorting to kernel. This could reduce context switch when the mutex is not heavily contended. However, if the mutex is hot, we could end up wasting spin time. Default: false
    
    Specified by:
    
    setUseAdaptiveMutex in interface DBOptionsInterface
    
    Parameters:
    useAdaptiveMutex - true if adaptive mutex is used.
    
    Returns:
    the instance of the current Object.
  - useAdaptiveMutex
```
public boolean useAdaptiveMutex()
```
    Description copied from interface: DBOptionsInterface
    
    Use adaptive mutex, which spins in the user space before resorting to kernel. This could reduce context switch when the mutex is not heavily contended. However, if the mutex is hot, we could end up wasting spin time. Default: false
    
    Specified by:
    
    useAdaptiveMutex in interface DBOptionsInterface
    
    Returns:
    true if adaptive mutex is used.
  - setBytesPerSync
```
public DBOptions setBytesPerSync(long bytesPerSync)
```
    Description copied from interface: DBOptionsInterface
    
    Allows OS to incrementally sync files to disk while they are being written, asynchronously, in the background. Issue one request for every bytes_per_sync written. 0 turns it off. Default: 0
    
    Specified by:
    
    setBytesPerSync in interface DBOptionsInterface
    
    Parameters:
    bytesPerSync - size in bytes
    
    Returns:
    the instance of the current Object.
  - bytesPerSync
```
public long bytesPerSync()
```
    Description copied from interface: DBOptionsInterface
    
    Allows OS to incrementally sync files to disk while they are being written, asynchronously, in the background. Issue one request for every bytes_per_sync written. 0 turns it off. Default: 0
    
    Specified by:
    
    bytesPerSync in interface DBOptionsInterface
    
    Returns:
    size in bytes
  - disposeInternal
```
protected void disposeInternal()
```
    Release the memory allocated for the current instance in the c++ side.
    
    Specified by:
    
    disposeInternal in class RocksObject

Class DBOptions

Field Summary

Fields inherited from class org.rocksdb.RocksObject

Constructor Summary

Method Summary

Methods inherited from class org.rocksdb.RocksObject

Methods inherited from class java.lang.Object

Constructor Detail

DBOptions

Method Detail

getDBOptionsFromProps

setIncreaseParallelism

setCreateIfMissing

createIfMissing

setCreateMissingColumnFamilies

createMissingColumnFamilies

setErrorIfExists

errorIfExists

setParanoidChecks

paranoidChecks

setRateLimiterConfig

setLogger

setInfoLogLevel

infoLogLevel

setMaxOpenFiles

maxOpenFiles

setMaxTotalWalSize

maxTotalWalSize

createStatistics

statisticsPtr

setDisableDataSync

disableDataSync

setUseFsync

useFsync

setDbLogDir

dbLogDir

setWalDir

walDir

setDeleteObsoleteFilesPeriodMicros

deleteObsoleteFilesPeriodMicros

setMaxBackgroundCompactions

maxBackgroundCompactions

setMaxBackgroundFlushes

maxBackgroundFlushes

setMaxLogFileSize

maxLogFileSize

setLogFileTimeToRoll

logFileTimeToRoll

setKeepLogFileNum

keepLogFileNum

setMaxManifestFileSize

maxManifestFileSize

setTableCacheNumshardbits

tableCacheNumshardbits

setTableCacheRemoveScanCountLimit

tableCacheRemoveScanCountLimit

setWalTtlSeconds

walTtlSeconds

setWalSizeLimitMB

walSizeLimitMB

setManifestPreallocationSize

manifestPreallocationSize

setAllowOsBuffer

allowOsBuffer

setAllowMmapReads

allowMmapReads

setAllowMmapWrites

allowMmapWrites

setIsFdCloseOnExec

isFdCloseOnExec

setSkipLogErrorOnRecovery

skipLogErrorOnRecovery

setStatsDumpPeriodSec

statsDumpPeriodSec

setAdviseRandomOnOpen

adviseRandomOnOpen

setUseAdaptiveMutex

useAdaptiveMutex

setBytesPerSync

bytesPerSync