DatabaseEnvironment Properties

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Berkeley DB .NET API Documentation
DatabaseEnvironment Properties
DatabaseEnvironment Class See Also Send Feedback

The DatabaseEnvironment type exposes the following members.

# Properties

| Name | Description
--- | --- | ---
| AutoCommit | If true, database operations for which no explicit transaction handle was specified, and which modify databases in the database environment, are automatically enclosed within a transaction.
| BackupBufferSize | The size of the buffer, in bytes, to read from the database during a hot backup.
| BackupHandler | Sets the IBackup interface to be used when performing hot backups. This interface is used to override the default behavior used by the Backup(String, BackupOptions) and BackupDatabase(String, String, Boolean) methods.
| BackupReadCount | The number of pages to read before pausing during the hot backup. Increasing this value increases the amount of I/O the backup process performs for any given time interval. If your application is already heavily I/O bound, setting this value to a lower number may help to improve your overall data throughput by reducing the I/O demands placed on your system. By default, all pages are read without a pause.
| BackupReadSleepDuration | The number of microseconds to sleep between batches of reads during a hot backup. Increasing this value decreases the amount of I/O the backup process performs for any given time interval. If your application is already heavily I/O bound, setting this value to a higher number may help to improve your overall data throughput by reducing the I/O demands placed on your system.
| BackupWriteDirect | If true, direct I/O is used when writing pages to the disk during a hot backup. For some environments, direct I/O can provide faster write throughput, but usually it is slower because the OS buffer pool offers asynchronous activity.
| BlobDir | Deprecated. Replaced by ExternalFileDir.
| BlobThreshold | Deprecated. Replaced by ExternalFileThreshold.
| CacheSize | The size of the shared memory buffer pool (the cache).
| CDB_ALLDB | If true, Berkeley DB Concurrent Data Store applications perform locking on an environment-wide basis rather than on a per-database basis.
| Create | If true, Berkeley DB subsystems create any underlying files, as necessary.
| DataDirs | The array of directories where database files are stored.
| DeadlockResolution | The deadlock detector configuration, specifying which lock request(s) should be rejected. As transactions acquire locks on behalf of a single locker ID, rejecting a lock request associated with a transaction normally requires the transaction to be aborted.
| EncryptAlgorithm | The algorithm used by the Berkeley DB library to perform encryption and decryption.
| ErrorFeedback | The mechanism for reporting detailed error messages to the application.
| ErrorPrefix | The prefix string that appears before error messages issued by Berkeley DB.
| EventNotify | A delegate which is called to notify the process of specific Berkeley DB events.
| ExternalFileDir | The path of the directory where external files are stored.
| ExternalFileThreshold | The size in bytes which is used to determine when a data item is stored as an external file. Any data item that is equal to or larger in size than the threshold value is automatically stored as an external file. If the threshold value is 0, databases opened in the environment default to never using external file support.
| Feedback | Monitor progress within long running operations.
| ForceFlush | If true, flush database writes to the backing disk before returning from the write system call, rather than flushing database writes explicitly in a separate system call, as necessary.
| FreeThreaded | If true, the object is free-threaded; that is, concurrently usable by multiple threads in the address space.
| Home | The database environment home directory.
| HotbackupInProgress | Whether there is any hot backup in progress.
| InitDatabaseCount | The number of databases initialized when the environment is created
| InitDatabaseLength | The maximum length of database's directory and name strings initialized when the environment is created
| InitExtFileDatabaseCount | The number of databases and subdatabases using external files initialized when the environment is created
| InitLockCount | The number of locks allocated when the environment is created
| InitLockerCount | The number of lockers allocated when the environment is created
| InitLockObjectCount | The number of lock objects allocated when the environment is created
| InitLogIdCount | The number of log identifier objects allocated when the environment is created
| InitMutexes | The initial number of mutexes allocated
| InitRegions | If true, Berkeley DB page-faults shared regions into memory when initially creating or joining a Berkeley DB environment.
| InitRepSitesCount | The maximum number of replication sites initialized when the environment is created
| InitThreadCount | The number of thread objects allocated when the environment is created
| InitTxnCount | The number of transaction objects allocated when the environment is created
| IntermediateDirMode | The intermediate directory permissions.
| LockConflictMatrix | The current lock conflicts array.
| Lockdown | If true, lock shared Berkeley DB environment files and memory-mapped databases into memory.
| LockPartitions | The number of lock table partitions used in the Berkeley DB environment.
| LockTableSize | The size of the lock table in the Berkeley DB environment.
| LockTimeout | A value, in microseconds, representing lock timeouts.
| LogAutoRemove | If true, Berkeley DB automatically removes log files that are no longer needed.
| LogBlobContent | Deprecated. Replaced by LogExternalFileContent
| LogBufferSize | The size of the in-memory log buffer, in bytes
| LogDir | The path of a directory to be used as the location of logging files. Log files created by the Log Manager subsystem are created in this directory.
| LogExternalFileContent | If true, enables full logging of external file data. Required if using HA or the hotbackup utility.
| LogFileMode | The absolute file mode for created log files. This property is only useful for the rare Berkeley DB application that does not control its umask value.
| LogForceSync | If true, Berkeley DB flushes log writes to the backing disk before returning from the write system call, rather than flushing log writes explicitly in a separate system call, as necessary.
| LogInMemory | If true, transaction logs are maintained in-memory rather than on disk. This means that transactions exhibit the ACI (atomicity, consistency, and isolation) properties, but not D (durability).
| LogNoBuffer | If true, system buffering is turned off for Berkeley DB log files to avoid double caching.
| LogNoSync | If true, Berkeley DB avoids the fsync() call when the log files are flushed.
| LogRegionSize | The size of the underlying logging area of the Berkeley DB environment, in bytes.
| LogZeroOnCreate | If true, all pages of a log file are zeroed when that log file is created.
| MaxCacheSize | The maximum cache size
| MaxLockers | The maximum number of locking entities supported by the Berkeley DB environment.
| MaxLocks | The maximum number of locks supported by the Berkeley DB environment.
| MaxLogFileSize | The maximum size of a single file in the log, in bytes. Because LSN Offsets are unsigned four-byte values, the size may not be larger than the maximum unsigned four-byte value.
| MaxMutexes | The total number of mutexes allocated
| MaxObjects | The maximum number of locked objects
| MaxOpenFiles | The number of file descriptors the library opens concurrently when flushing dirty pages from the cache.
| MaxSequentialWrites | The number of sequential write operations scheduled by the library when flushing dirty pages from the cache.
| MaxTransactions | The number of active transactions supported by the environment. This value bounds the size of the memory allocated for transactions. Child transactions are counted as active until they either commit or abort.
| messageFeedback | The mechanism for reporting detailed statistic messages to the application.
| MessagePrefix | The prefix string that appears before informational messages issued by Berkeley DB.
| MetadataDir | The path of directory to store the persistent metadata.
| MMapSize | The maximum file size, in bytes, for a file to be mapped into the process address space. If no value is specified, it defaults to 10MB.
| Msgfile | The message file.
| MutexAlignment | The mutex alignment, in bytes.
| MutexIncrement | The number of additional mutexes allocated.
| NoBuffer | If true, turn off system buffering of Berkeley DB database files to avoid double caching.
| NoLocking | If true, Berkeley DB grants all requested mutual exclusion mutexes and database locks without regard for their actual availability. This functionality should never be used for purposes other than debugging.
| NoMMap | If true, Berkeley DB copies read-only database files into the local cache instead of potentially mapping them into process memory.
| NoPanic | If true, Berkeley DB ignores any panic state in the database environment. (Database environments in a panic state normally refuse all attempts to call Berkeley DB functions, throwing RunRecoveryException.) This functionality should never be used for purposes other than debugging.
| NumTestAndSetSpins | The number of times that test-and-set mutexes should spin without blocking. The value defaults to 1 on uniprocessor systems and to 50 times the number of processors on multiprocessor systems.
| Overwrite | If true, overwrite files stored in encrypted formats before deleting them.
| Private | If true, allocate region memory from the heap instead of from memory backed by the filesystem or system shared memory.
| RegionDir | The path of a directory to be used as the location of region files. Region files created by the Environment are stored in this directory.
| RegionMemoryLimitBytes | The bytes component of the byte-count limit on the amount of memory to be used by shared structures in the main environment region. These are the structures other than mutexes and the page cache (memory pool).
| RegionMemoryLimitGBytes | The gigabytes component of the byte-count limit on the amount of memory to be used by shared structures in the main environment region. These are the structures other than mutexes and the page cache (memory pool).
| Register | If true, Berkeley DB checks if recovery is needed to be performed before opening the database environment.
| RepAckTimeout | The amount of time the replication manager's transport function waits to collect enough acknowledgments from replication group clients, before giving up and returning a failure indication. The default wait time is 1 second.
| RepAutoInit | If true, the replication master automatically re-initializes outdated clients (defaults to true).
| RepBulkTransfer | If true, the replication master sends groups of records to the clients in a single network transfer
| RepCheckpointDelay | The amount of time a master site delays between completing a checkpoint and writing a checkpoint record into the log.
| RepClockskewFast | The value, relative to RepClockskewSlow, of the fastest clock in the group of sites.
| RepClockskewSlow | The value of the slowest clock in the group of sites.
| RepConnectionRetry | The amount of time the replication manager waits before trying to re-establish a connection to another site after a communication failure. The default wait time is 30 seconds.
| RepDelayClientSync | If true, the client should delay synchronizing to a newly declared master (defaults to false). Clients configured in this way remain unsynchronized until the application calls RepSync()()().
| RepDisablePoll | This flag is used to prevent the use of poll() as polling method for networking events on the target site. This flag guarantees that instead of poll() select or epoll() would be used depending on the availablity of these methods on the target platform and additional flags provided to repmgr.
| RepDisableSSL | This flag is used to prevent the use of SSL for securing the messages exchanged between nodes in a replication group.
| RepElectionRetry | Configure the amount of time the replication manager waits before retrying a failed election. The default wait time is 10 seconds.
| RepElectionTimeout | The timeout period for an election. The default timeout is 2 seconds.
| RepEnableEpoll | This flag is used to force the use of epoll as polling method for networking events instad of poll or select. Use of this flag does not guarantee that epoll will be used though. It depends on the availability of epoll on target platform. Epoll is supposed to be used only when the expected number of connections for repmgr is greater than 1000.
| RepForwardWrites | Enable simple write forwarding for this site. By default, write operations cannot be performed on a replication client site. This option enables forwarding of simple client put and delete operations to the master site for processing. These operations must use an implicit NULL transaction ID to be forwarded. Any other write operation that specifies a non-NULL transaction throws a DatabaseException. The master must have an open database handle for the database on which a forwarded write operation is being performed. All sites in the replication group should have the same value for this configuration option.
| RepFullElectionTimeout | An optional configuration timeout period to wait for full election participation the first time the replication group finds a master. By default this option is turned off and normal election timeouts are used. (See the Elections section in the Berkeley DB Reference Guide for more information.)
| RepHeartbeatMonitor | The amount of time the replication manager, running at a client site, waits for some message activity on the connection from the master (heartbeats or other messages) before concluding that the connection has been lost. When 0 (the default), no monitoring is performed.
| RepHeartbeatSend | The frequency at which the replication manager, running at a master site, broadcasts a heartbeat message in an otherwise idle system. When 0 (the default), no heartbeat messages are sent.
| RepInMemory | If true, replication only stores the internal information in-memory and cannot keep persistent state across a site crash or reboot. By default, it is false and replication creates files in the environment home directory to preserve the internal information.
| RepLeaseTimeout | The amount of time a client grants its master lease to a master. When using master leases all sites in a replication group must use the same lease timeout value. There is no default value. If leases are desired, this method must be called prior to calling RepStartClient()()() or RepStartMaster()()().
| ReplicationView | The function used to create a replication view that determines whether a database file is replicated to the local site.
| RepMessageDispatch | Set the message dispatch function. It is responsible for receiving messages sent from remote sites using either SendMessage(array<DatabaseEntry>[]()[]) or SendRequest(array<DatabaseEntry>[]()[], UInt32). If the message received by this function was sent using SendMessage(array<DatabaseEntry>[]()[]), then no response is required. If the message was sent using SendRequest(array<DatabaseEntry>[]()[], UInt32), then this function must send a response using SendMessage(array<DatabaseEntry>[]()[]).
| RepMgrAckPolicy | Specify how master and client sites handle acknowledgment of replication messages which are necessary for "permanent" records. The current implementation requires all sites in a replication group configure the same acknowledgement policy.
| RepmgrIncomingQueueMaxBytes | The bytes component of the maximum amount of dynamic memory used by the Replication Manager incoming queue.
| RepmgrIncomingQueueMaxGBytes | The gigabytes component of the maximum amount of dynamic memory used by the Replication Manager incoming queue.
| RepMgrLocalSite | The local site of the replication manager. Returns null if the local site has not been configured.
| RepMgrRemoteSites | The status of the sites currently known by the replication manager.
| RepMgrRunElections | If true, Replication Manager automatically runs elections to choose a new master when the old master disconnects (defaults to true).
| RepNoBlocking | If true, errors are returned immediately for Berkeley DB method calls that would normally block while clients are in recovery (defaults to false).
| RepNSites | The total number of sites in the replication group.
| RepPrefmasClient | This flag is used to specify the client site in a replication group operating in preferred master mode. A preferred master replication group must contain only two sites, with one site specified as the preferred master site and the other site specified as the client site. The client site in a preferred master replication group takes over temporarily as master when the preferred master site is unavailable.
| RepPrefmasMaster | This flag is used to specify the preferred master site in a replication group operating in preferred master mode. A preferred master replication group must contain only two sites, with one site specified as the preferred master site and the other site specified as the client site. The preferred master site operates as the master site whenever possible.
| RepPriority | The database environment's priority in replication group elections. A special value of 0 indicates that this environment cannot be a replication group master. If not configured, then a default value of 100 is used.
| RepRetransmissionRequestMax | The maximum number of microseconds a client waits before requesting retransmission.
| RepRetransmissionRequestMin | The minimum number of microseconds a client waits before requesting retransmission.
| RepStrict2Site | Replication Manager observes the strict "majority" rule in managing elections, even in a group with only 2 sites. The client in a 2-site group is unable to take over as master if the original master fails or becomes disconnected. (See the Elections section in the Berkeley DB Reference Guide for more information.) Both sites in the replication group should have the same value for this parameter.
| RepTransmitLimitBytes | The bytes component of the byte-count limit on the amount of data that is transmitted from a site in response to a single message processed by RepProcessMessage(DatabaseEntry, DatabaseEntry, Int32).
| RepTransmitLimitGBytes | The gigabytes component of the byte-count limit on the amount of data that is transmitted from a site in response to a single message processed by RepProcessMessage(DatabaseEntry, DatabaseEntry, Int32).
| RepTransport | The delegate used to transmit data using the replication application's communication infrastructure.
| RepUseMasterLeases | If true, master leases are used for this site (defaults to false).
| RepWriteForwardTimeout | Configure the amount of time a Replication Manager client waits for a response from a forwarded write operation before returning a failure indication. The default value is 5 seconds.
| RunFatalRecovery | If true, catastrophic recovery was run on this environment before opening it for normal use.
| RunRecovery | If true, normal recovery was run on this environment before opening it for normal use.
| SequentialWritePause | The number of microseconds the thread of control pauses before scheduling further write operations.
| SetThreadID | A delegate that returns a unique identifier pair for the current thread of control.
| SetThreadName | A delegate that formats a process ID and thread ID identifier pair.
| SystemMemory | If true, allocate region memory from system shared memory instead of from heap memory or memory backed by the filesystem.
| TempDir | The path of a directory to be used as the location for temporary files.
| ThreadCount | An approximate number of threads in the database environment.
| ThreadIsAlive | A delegate that returns if a thread of control (either a true thread or a process) is still running.
| TimeNotGranted | If true, database calls timing out based on lock or transaction timeout values throw LockNotGrantedException instead of DeadlockException.
| TxnNoSync | If true, Berkeley DB does not write or synchronously flush the log on transaction commit.
| TxnNoWait | If true and a lock is unavailable for any Berkeley DB operation performed in the context of a transaction, cause the operation to throw DeadlockException (or LockNotGrantedException if configured with TimeNotGranted).
| TxnSnapshot | If true, all transactions in the environment are started as if Snapshot was passed to BeginTransaction()()(), and all non-transactional cursors are opened as if SnapshotIsolation was passed to Cursor()()().
| TxnTimeout | A value, in microseconds, representing transaction timeouts.
| TxnTimestamp | The recovery timestamp
| TxnWriteNoSync | If true, Berkeley DB writes, but does not synchronously flush, the log on transaction commit.
| UseEnvironmentVars | The Berkeley DB process' environment may be permitted to specify information to be used when naming files; see Berkeley DB File Naming in the Programmer's Reference Guide for more information.
| UseMVCC | If true, all databases in the environment are opened as if UseMVCC was set.
| UsingCDB | If true, locking for the Berkeley DB Concurrent Data Store product was initialized.
| UsingLocking | If true, the locking subsystem was initialized.
| UsingLogging | If true, the logging subsystem was initialized.
| UsingMPool | If true, the shared memory buffer pool subsystem was initialized.
| UsingReplication | If true, the replication subsystem was initialized.
| UsingTxns | If true, the transaction subsystem was initialized.
| Verbosity | Specific additional informational and debugging messages in the Berkeley DB message output.
| YieldCPU | If true, Berkeley DB yields the processor immediately after each page or mutex acquisition.

# See Also

DatabaseEnvironment Class
BerkeleyDB Namespace