A connection to a WiredTiger database. More...

Public Member Functions
synchronized void	delete ()

int	async_flush () throws com.wiredtiger.db.WiredTigerException
	Wait for all outstanding operations to complete. More...

int	close (String config) throws com.wiredtiger.db.WiredTigerException
	Close a connection. More...

int	reconfigure (String config) throws com.wiredtiger.db.WiredTigerException
	Reconfigure a connection handle. More...

String	get_home ()

int	configure_method (String method, String uri, String config, String type, String check) throws com.wiredtiger.db.WiredTigerException
	Add configuration options for a method. More...

int	is_new ()
	Return if opening this handle created the database. More...

int	load_extension (String path, String config) throws com.wiredtiger.db.WiredTigerException
	Load an extension. More...

AsyncOp	async_new_op (String uri, String config, Object callbackObject) throws com.wiredtiger.db.WiredTigerException
	Return an async operation handle. More...

Session	open_session (String config) throws com.wiredtiger.db.WiredTigerException
	Open a session. More...

Protected Member Functions
	Connection (long cPtr, boolean cMemoryOwn)

int	java_init (Object jsess)

Static Protected Member Functions
static long	getCPtr (Connection obj)

Protected Attributes
boolean	swigCMemOwn

Detailed Description

A connection to a WiredTiger database.

The connection may be opened within the same address space as the caller or accessed over a socket connection.

Most applications will open a single connection to a database for each process. The first process to open a connection to a database will access the database in its own address space. Subsequent connections (if allowed) will communicate with the first process over a socket connection to perform their operations.

Thread safety: A WT_CONNECTION handle may be shared between threads, see Multithreading for more information.

Member Function Documentation

int com.wiredtiger.db.Connection.async_flush ( ) throws com.wiredtiger.db.WiredTigerException

Wait for all outstanding operations to complete.

/* Wait for all outstanding operations to complete. */

ret = conn->async_flush(conn);

Parameters

connection the connection handle

Returns: zero on success and a non-zero error code on failure. See Error Returns for details.

AsyncOp com.wiredtiger.db.Connection.async_new_op	(	String	uri,
		String	config,
		Object	callbackObject
	)		throws com.wiredtiger.db.WiredTigerException

Return an async operation handle.

                while ((ret = conn->async_new_op(conn,
                    "table:async", NULL, &ex_asynckeys.iface, &op)) != 0) {
                        /*
                         * If we used up all the handles, pause and retry to
                         * give the workers a chance to catch up.
                         */
                        fprintf(stderr,
                            "asynchronous operation handle not available\n");
                        if (ret == EBUSY)
                                sleep(1);
                        else
                                return (ret);
                }

Parameters

connection the connection handle

uri the connection handle

config

Configuration string, see Configuration Strings. Permitted values:

Name	Effect	Values
`append`	append the value as a new record, creating a new record number key; valid only for operations with record number keys.	a boolean flag; default `false`.
`overwrite`	configures whether the cursor's insert, update and remove methods check the existing state of the record. If `overwrite` is `false`, WT_CURSOR::insert fails with WT_DUPLICATE_KEY if the record exists, WT_CURSOR::update and WT_CURSOR::remove fail with WT_NOTFOUND if the record does not exist.	a boolean flag; default `true`.
`raw`	ignore the encodings for the key and value, manage data as if the formats were `"u"`. See Raw mode for details.	a boolean flag; default `false`.
`timeout`	maximum amount of time to allow for compact in seconds. The actual amount of time spent in compact may exceed the configured value. A value of zero disables the timeout.	an integer; default `1200`.

callback the operation callback

[out] asyncopp the new op handle

Returns: zero on success and a non-zero error code on failure. See Error Returns for details. If there are no available handles, EBUSY is returned.

int com.wiredtiger.db.Connection.close ( String config ) throws com.wiredtiger.db.WiredTigerException

Close a connection.

Any open sessions will be closed.

ret = conn->close(conn, NULL);

Parameters

connection the connection handle

config

Configuration string, see Configuration Strings. Permitted values:

Name	Effect	Values
`leak_memory`	don't free memory during close.	a boolean flag; default `false`.

Returns: zero on success and a non-zero error code on failure. See Error Returns for details.

int com.wiredtiger.db.Connection.configure_method	(	String	method,
		String	uri,
		String	config,
		String	type,
		String	check
	)		throws com.wiredtiger.db.WiredTigerException

Add configuration options for a method.

See Creating data-specific configuration strings for more information.

        /*
         * Applications opening a cursor for the data-source object "my_data"
         * have an additional configuration option "entries", which is an
         * integer type, defaults to 5, and must be an integer between 1 and 10.
         */
        ret = conn->configure_method(conn,
            "session.open_cursor",
            "my_data:", "entries=5", "int", "min=1,max=10");
        /*
         * Applications opening a cursor for the data-source object "my_data"
         * have an additional configuration option "devices", which is a list
         * of strings.
         */
        ret = conn->configure_method(conn,
            "session.open_cursor", "my_data:", "devices", "list", NULL);

Parameters

connection	the connection handle
method	the name of the method
uri	the object type or NULL for all object types
config	the additional configuration's name and default value
type	the additional configuration's type (must be one of `"boolean"\`, `"int"`, `"list"` or `"string"`)
check	the additional configuration check string, or NULL if none

Returns: zero on success and a non-zero error code on failure. See Error Returns for details.

int com.wiredtiger.db.Connection.is_new ( )

Return if opening this handle created the database.

        if (conn->is_new(conn)) {
                /* First time initialization. */
        }

Parameters

connection the connection handle

Returns: false (zero) if the connection existed before the call to wiredtiger_open, true (non-zero) if it was created by opening this handle.

int com.wiredtiger.db.Connection.load_extension	(	String	path,
		String	config
	)		throws com.wiredtiger.db.WiredTigerException

Load an extension.

        ret = conn->load_extension(conn, "my_extension.dll", NULL);
        ret = conn->load_extension(conn,
            "datasource/libdatasource.so",
            "config=[device=/dev/sd1,alignment=64]");

Parameters

connection the connection handle

path the filename of the extension module, or "local" to search the current application binary for the initialization function, see Extending WiredTiger for more details.

config

Configuration string, see Configuration Strings. Permitted values:

Name	Effect	Values
`config`	configuration string passed to the entry point of the extension as its WT_CONFIG_ARG argument.	a string; default empty.
`entry`	the entry point of the extension, called to initialize the extension when it is loaded. The signature of the function must match wiredtiger_extension_init.	a string; default `wiredtiger_extension_init`.
`terminate`	an optional function in the extension that is called before the extension is unloaded during WT_CONNECTION::close. The signature of the function must match wiredtiger_extension_terminate.	a string; default `wiredtiger_extension_terminate`.

Returns: zero on success and a non-zero error code on failure. See Error Returns for details.

Session com.wiredtiger.db.Connection.open_session ( String config ) throws com.wiredtiger.db.WiredTigerException

Open a session.

WT_SESSION *session;

ret = conn->open_session(conn, NULL, NULL, &session);

Parameters

connection the connection handle

errhandler An error handler. If NULL, the connection's error handler is used

config

Configuration string, see Configuration Strings. Permitted values:

Name	Effect	Values
`isolation`	the default isolation level for operations in this session.	a string, chosen from the following options: `"read-uncommitted"`, `"read-committed"`, `"snapshot"`; default `read-committed`.

[out] sessionp the new session handle

Returns: zero on success and a non-zero error code on failure. See Error Returns for details.

int com.wiredtiger.db.Connection.reconfigure ( String config ) throws com.wiredtiger.db.WiredTigerException

Reconfigure a connection handle.

ret = conn->reconfigure(conn, "eviction_target=75");

Parameters

connection the connection handle

config

Configuration string, see Configuration Strings. Permitted values:

Name	Effect	Values
`async = (`	asynchronous operations configuration options.	a set of related configuration options defined below.
`enabled`	enable asynchronous operation.	a boolean flag; default `false`.
`ops_max`	maximum number of expected simultaneous asynchronous operations.	an integer between 10 and 4096; default `1024`.
`threads`	the number of worker threads to service asynchronous requests.	an integer between 1 and 20; default `2`.
`)`
`cache_size`	maximum heap memory to allocate for the cache. A database should configure either a cache_size or a shared_cache not both.	an integer between 1MB and 10TB; default `100MB`.
`checkpoint = (`	periodically checkpoint the database.	a set of related configuration options defined below.
`log_size`	wait for this amount of log record bytes to be written to the log between each checkpoint. A database can configure both log_size and wait to set an upper bound for checkpoints; setting this value above 0 configures periodic checkpoints.	an integer between 0 and 2GB; default `0`.
`name`	the checkpoint name.	a string; default `"WiredTigerCheckpoint"`.
`wait`	seconds to wait between each checkpoint; setting this value above 0 configures periodic checkpoints.	an integer between 0 and 100000; default `0`.
`)`
`error_prefix`	prefix string for error messages.	a string; default empty.
`eviction = (`	eviction configuration options.	a set of related configuration options defined below.
`threads_max`	maximum number of threads WiredTiger will start to help evict pages from cache. The number of threads started will vary depending on the current eviction load.	an integer between 1 and 20; default `1`.
`threads_min`	minimum number of threads WiredTiger will start to help evict pages from cache. The number of threads currently running will vary depending on the current eviction load.	an integer between 1 and 20; default `1`.
`)`
`eviction_dirty_target`	continue evicting until the cache has less dirty memory than the value, as a percentage of the total cache size. Dirty pages will only be evicted if the cache is full enough to trigger eviction.	an integer between 10 and 99; default `80`.
`eviction_target`	continue evicting until the cache has less total memory than the value, as a percentage of the total cache size. Must be less than `eviction_trigger`.	an integer between 10 and 99; default `80`.
`eviction_trigger`	trigger eviction when the cache is using this much memory, as a percentage of the total cache size.	an integer between 10 and 99; default `95`.
`lsm_manager = (`	configure database wide options for LSM tree management.	a set of related configuration options defined below.
`merge`	merge LSM chunks where possible.	a boolean flag; default `true`.
`worker_thread_max`	Configure a set of threads to manage merging LSM trees in the database.	an integer between 3 and 20; default `4`.
`)`
`shared_cache = (`	shared cache configuration options. A database should configure either a cache_size or a shared_cache not both.	a set of related configuration options defined below.
`chunk`	the granularity that a shared cache is redistributed.	an integer between 1MB and 10TB; default `10MB`.
`name`	name of a cache that is shared between databases.	a string; default empty.
`reserve`	amount of cache this database is guaranteed to have available from the shared cache. This setting is per database. Defaults to the chunk size.	an integer; default `0`.
`size`	maximum memory to allocate for the shared cache. Setting this will update the value if one is already set.	an integer between 1MB and 10TB; default `500MB`.
`)`
`statistics`	Maintain database statistics, which may impact performance. Choosing "all" maintains all statistics regardless of cost, "fast" maintains a subset of statistics that are relatively inexpensive, "none" turns off all statistics. The "clear" configuration resets statistics after they are gathered, where appropriate (for example, a cache size statistic is not cleared, while the count of cursor insert operations will be cleared). When "clear" is configured for the database, gathered statistics are reset each time a statistics cursor is used to gather statistics, as well as each time statistics are logged using the `statistics_log` configuration. See Statistics for more information.	a list, with values chosen from the following options: `"all"`, `"fast"`, `"none"`, `"clear"`; default `none`.
`statistics_log = (`	log any statistics the database is configured to maintain, to a file. See Statistics for more information.	a set of related configuration options defined below.
`on_close`	log statistics on database close.	a boolean flag; default `false`.
`path`	the pathname to a file into which the log records are written, may contain ISO C standard strftime conversion specifications. If the value is not an absolute path name, the file is created relative to the database home.	a string; default `"WiredTigerStat.%d.%H"`.
`sources`	if non-empty, include statistics for the list of data source URIs, if they are open at the time of the statistics logging. The list may include URIs matching a single data source ("table:mytable"), or a URI matching all data sources of a particular type ("table:").	a list of strings; default empty.
`timestamp`	a timestamp prepended to each log record, may contain strftime conversion specifications.	a string; default `"%b %d %H:%M:%S"`.
`wait`	seconds to wait between each write of the log records.	an integer between 0 and 100000; default `0`.
`)`
`verbose`	enable messages for various events. Only available if WiredTiger is configured with –enable-verbose. Options are given as a list, such as `"verbose=[evictserver,read]"`.	a list, with values chosen from the following options: `"api"`, `"block"`, `"checkpoint"`, `"compact"`, `"evict"`, `"evictserver"`, `"fileops"`, `"log"`, `"lsm"`, `"metadata"`, `"mutex"`, `"overflow"`, `"read"`, `"reconcile"`, `"recovery"`, `"salvage"`, `"shared_cache"`, `"split"`, `"temporary"`, `"transaction"`, `"verify"`, `"version"`, `"write"`; default empty.

Returns: zero on success and a non-zero error code on failure. See Error Returns for details.

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation