com.wiredtiger.db.Connection Class Reference

A connection to a WiredTiger database. More...

Public Member Functions
synchronized void	delete ()
int	close (String config)
	Close a connection. More...
int	reconfigure (String config)
	Reconfigure a connection handle. More...
String	get_home ()
int	configure_method (String method, String uri, String config, String type, String check)
	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)
	Load an extension. More...
Session	open_session (String config)

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.close

(

String

config

)

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. No values currently permitted.

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
	)

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
	)

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
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.

int com.wiredtiger.db.Connection.reconfigure

(

String

config

)

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 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. error_prefix prefix string for error messages. a string; default empty. eviction_dirty_target continue evicting until the cache has less dirty pages than this (as a percentage). 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 becomes less full than this (as a percentage). Must be less than eviction_trigger. an integer between 10 and 99; default 80. eviction_trigger trigger eviction when the cache becomes this full (as a percentage). an integer between 10 and 99; default 95. 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.     enable whether the connection is using a shared cache. a boolean flag; default false.     chunk the granularity that a shared cache is redistributed. an integer between 1MB and 10TB; default 10MB.     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.     name name of a cache that is shared between databases. a string; default pool.     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. verbose enable messages for various events. Options are given as a list, such as "verbose=[evictserver,read]". a list, with values chosen from the following options: "block", "ckpt", "compact", "evict", "evictserver", "fileops", "hazard", "log", "lsm", "mutex", "overflow", "read", "readserver", "reconcile", "recovery", "salvage", "shared_cache", "verify", "version", "write"; default empty.

Returns

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