Version 3.0.0
WiredTiger API

The functions, handles and methods applications use to access and manage data with WiredTiger. More...

Classes

struct  WT_ITEM
 A raw item of data to be managed, including a pointer to the data and a length. More...
 
struct  WT_MODIFY
 A set of modifications for a value, including a pointer to new data and a length, plus a target offset in the value and an optional length of data in the value to be replaced. More...
 
struct  WT_CURSOR
 A WT_CURSOR handle is the interface to a cursor. More...
 
struct  WT_ASYNC_OP
 A WT_ASYNC_OP handle is the interface to an asynchronous operation. More...
 
struct  WT_SESSION
 All data operations are performed in the context of a WT_SESSION. More...
 
struct  WT_CONNECTION
 A connection to a WiredTiger database. More...
 
struct  WT_ASYNC_CALLBACK
 The interface implemented by applications to accept notifications of the completion of asynchronous operations. More...
 
struct  WT_EVENT_HANDLER
 The interface implemented by applications to handle error, informational and progress messages. More...
 
struct  WT_CONFIG_ITEM
 The configuration information returned by the WiredTiger configuration parsing functions in the WT_EXTENSION_API and the public API. More...
 
struct  WT_CONFIG_PARSER
 A handle that can be used to search and traverse configuration strings compatible with WiredTiger APIs. More...
 

Macros

#define WT_INTPACK64_MAXSIZE
 The maximum packed size of a 64-bit integer. More...
 
#define WT_INTPACK32_MAXSIZE
 The maximum packed size of a 32-bit integer. More...
 

Enumerations

enum  WT_ASYNC_OPTYPE {
  WT_AOP_NONE, WT_AOP_COMPACT, WT_AOP_INSERT, WT_AOP_REMOVE,
  WT_AOP_SEARCH, WT_AOP_UPDATE
}
 Asynchronous operation types. More...
 

Functions

int wiredtiger_open (const char *home, WT_EVENT_HANDLER *errhandler, const char *config, WT_CONNECTION **connectionp)
 Open a connection to a database. More...
 
const char * wiredtiger_strerror (int error)
 Return information about a WiredTiger error as a string (see WT_SESSION::strerror for a thread-safe API). More...
 
const char * wiredtiger_version (int *majorp, int *minorp, int *patchp)
 Get version information. More...
 

Data packing and unpacking

typedef struct __wt_pack_stream WT_PACK_STREAM
 Streaming interface to packing. More...
 
int wiredtiger_struct_pack (WT_SESSION *session, void *buffer, size_t size, const char *format,...)
 Pack a structure into a buffer. More...
 
int wiredtiger_struct_size (WT_SESSION *session, size_t *sizep, const char *format,...)
 Calculate the size required to pack a structure. More...
 
int wiredtiger_struct_unpack (WT_SESSION *session, const void *buffer, size_t size, const char *format,...)
 Unpack a structure from a buffer. More...
 
int wiredtiger_pack_start (WT_SESSION *session, const char *format, void *buffer, size_t size, WT_PACK_STREAM **psp)
 Start a packing operation into a buffer with the given format string. More...
 
int wiredtiger_unpack_start (WT_SESSION *session, const char *format, const void *buffer, size_t size, WT_PACK_STREAM **psp)
 Start an unpacking operation from a buffer with the given format string. More...
 
int wiredtiger_pack_close (WT_PACK_STREAM *ps, size_t *usedp)
 Close a packing stream. More...
 
int wiredtiger_pack_item (WT_PACK_STREAM *ps, WT_ITEM *item)
 Pack an item into a packing stream. More...
 
int wiredtiger_pack_int (WT_PACK_STREAM *ps, int64_t i)
 Pack a signed integer into a packing stream. More...
 
int wiredtiger_pack_str (WT_PACK_STREAM *ps, const char *s)
 Pack a string into a packing stream. More...
 
int wiredtiger_pack_uint (WT_PACK_STREAM *ps, uint64_t u)
 Pack an unsigned integer into a packing stream. More...
 
int wiredtiger_unpack_item (WT_PACK_STREAM *ps, WT_ITEM *item)
 Unpack an item from a packing stream. More...
 
int wiredtiger_unpack_int (WT_PACK_STREAM *ps, int64_t *ip)
 Unpack a signed integer from a packing stream. More...
 
int wiredtiger_unpack_str (WT_PACK_STREAM *ps, const char **sp)
 Unpack a string from a packing stream. More...
 
int wiredtiger_unpack_uint (WT_PACK_STREAM *ps, uint64_t *up)
 Unpack an unsigned integer from a packing stream. More...
 

Configuration strings

int wiredtiger_config_parser_open (WT_SESSION *session, const char *config, size_t len, WT_CONFIG_PARSER **config_parserp)
 Create a handle that can be used to parse or create configuration strings compatible with WiredTiger APIs. More...
 

Error returns

Most functions and methods in WiredTiger return an integer code indicating whether the operation succeeded or failed.

A return of zero indicates success, all non-zero return values indicate some kind of failure.

WiredTiger reserves all values from -31,800 to -31,999 as possible error return values. WiredTiger may also return C99/POSIX error codes such as ENOMEM, EINVAL and ENOTSUP, with the usual meanings.

The following are all of the WiredTiger-specific error returns:

#define WT_ROLLBACK
 Conflict between concurrent operations. More...
 
#define WT_DUPLICATE_KEY
 Attempt to insert an existing key. More...
 
#define WT_ERROR
 Non-specific WiredTiger error. More...
 
#define WT_NOTFOUND
 Item not found. More...
 
#define WT_PANIC
 WiredTiger library panic. More...
 
#define WT_RUN_RECOVERY
 Recovery must be run to continue. More...
 
#define WT_CACHE_FULL
 Operation would overflow cache. More...
 

Log record and operation types

#define WT_LOGREC_CHECKPOINT
 checkpoint
 
#define WT_LOGREC_COMMIT
 transaction commit
 
#define WT_LOGREC_FILE_SYNC
 file sync
 
#define WT_LOGREC_MESSAGE
 message
 
#define WT_LOGREC_SYSTEM
 system/internal record
 
#define WT_LOGOP_INVALID
 invalid operation
 
#define WT_LOGOP_COL_PUT
 column-store put
 
#define WT_LOGOP_COL_REMOVE
 column-store remove
 
#define WT_LOGOP_COL_TRUNCATE
 column-store truncate
 
#define WT_LOGOP_ROW_PUT
 row-store put
 
#define WT_LOGOP_ROW_REMOVE
 row-store remove
 
#define WT_LOGOP_ROW_TRUNCATE
 row-store truncate
 
#define WT_LOGOP_CHECKPOINT_START
 checkpoint start
 
#define WT_LOGOP_PREV_LSN
 previous LSN
 
#define WT_LOGOP_COL_MODIFY
 column-store modify
 
#define WT_LOGOP_ROW_MODIFY
 row-store modify
 

Connection statistics

Statistics are accessed through cursors with "statistics:" URIs. Individual statistics can be queried through the cursor using the following keys. See Statistics Data for more information.

#define WT_STAT_CONN_LSM_WORK_QUEUE_APP
 LSM: application work units currently queued.
 
#define WT_STAT_CONN_LSM_WORK_QUEUE_MANAGER
 LSM: merge work units currently queued.
 
#define WT_STAT_CONN_LSM_ROWS_MERGED
 LSM: rows merged in an LSM tree.
 
#define WT_STAT_CONN_LSM_CHECKPOINT_THROTTLE
 LSM: sleep for LSM checkpoint throttle.
 
#define WT_STAT_CONN_LSM_MERGE_THROTTLE
 LSM: sleep for LSM merge throttle.
 
#define WT_STAT_CONN_LSM_WORK_QUEUE_SWITCH
 LSM: switch work units currently queued.
 
#define WT_STAT_CONN_LSM_WORK_UNITS_DISCARDED
 LSM: tree maintenance operations discarded.
 
#define WT_STAT_CONN_LSM_WORK_UNITS_DONE
 LSM: tree maintenance operations executed.
 
#define WT_STAT_CONN_LSM_WORK_UNITS_CREATED
 LSM: tree maintenance operations scheduled.
 
#define WT_STAT_CONN_LSM_WORK_QUEUE_MAX
 LSM: tree queue hit maximum.
 
#define WT_STAT_CONN_ASYNC_CUR_QUEUE
 async: current work queue length
 
#define WT_STAT_CONN_ASYNC_MAX_QUEUE
 async: maximum work queue length
 
#define WT_STAT_CONN_ASYNC_ALLOC_RACE
 async: number of allocation state races
 
#define WT_STAT_CONN_ASYNC_FLUSH
 async: number of flush calls
 
#define WT_STAT_CONN_ASYNC_ALLOC_VIEW
 async: number of operation slots viewed for allocation
 
#define WT_STAT_CONN_ASYNC_FULL
 async: number of times operation allocation failed
 
#define WT_STAT_CONN_ASYNC_NOWORK
 async: number of times worker found no work
 
#define WT_STAT_CONN_ASYNC_OP_ALLOC
 async: total allocations
 
#define WT_STAT_CONN_ASYNC_OP_COMPACT
 async: total compact calls
 
#define WT_STAT_CONN_ASYNC_OP_INSERT
 async: total insert calls
 
#define WT_STAT_CONN_ASYNC_OP_REMOVE
 async: total remove calls
 
#define WT_STAT_CONN_ASYNC_OP_SEARCH
 async: total search calls
 
#define WT_STAT_CONN_ASYNC_OP_UPDATE
 async: total update calls
 
#define WT_STAT_CONN_BLOCK_PRELOAD
 block-manager: blocks pre-loaded
 
#define WT_STAT_CONN_BLOCK_READ
 block-manager: blocks read
 
#define WT_STAT_CONN_BLOCK_WRITE
 block-manager: blocks written
 
#define WT_STAT_CONN_BLOCK_BYTE_READ
 block-manager: bytes read
 
#define WT_STAT_CONN_BLOCK_BYTE_WRITE
 block-manager: bytes written
 
#define WT_STAT_CONN_BLOCK_BYTE_WRITE_CHECKPOINT
 block-manager: bytes written for checkpoint
 
#define WT_STAT_CONN_BLOCK_MAP_READ
 block-manager: mapped blocks read
 
#define WT_STAT_CONN_BLOCK_BYTE_MAP_READ
 block-manager: mapped bytes read
 
#define WT_STAT_CONN_CACHE_READ_APP_COUNT
 cache: application threads page read from disk to cache count
 
#define WT_STAT_CONN_CACHE_READ_APP_TIME
 cache: application threads page read from disk to cache time (usecs)
 
#define WT_STAT_CONN_CACHE_WRITE_APP_COUNT
 cache: application threads page write from cache to disk count
 
#define WT_STAT_CONN_CACHE_WRITE_APP_TIME
 cache: application threads page write from cache to disk time (usecs)
 
#define WT_STAT_CONN_CACHE_BYTES_IMAGE
 cache: bytes belonging to page images in the cache
 
#define WT_STAT_CONN_CACHE_BYTES_INUSE
 cache: bytes currently in the cache
 
#define WT_STAT_CONN_CACHE_BYTES_OTHER
 cache: bytes not belonging to page images in the cache
 
#define WT_STAT_CONN_CACHE_BYTES_READ
 cache: bytes read into cache
 
#define WT_STAT_CONN_CACHE_BYTES_WRITE
 cache: bytes written from cache
 
#define WT_STAT_CONN_CACHE_EVICTION_CHECKPOINT
 cache: checkpoint blocked page eviction
 
#define WT_STAT_CONN_CACHE_EVICTION_GET_REF
 cache: eviction calls to get a page
 
#define WT_STAT_CONN_CACHE_EVICTION_GET_REF_EMPTY
 cache: eviction calls to get a page found queue empty
 
#define WT_STAT_CONN_CACHE_EVICTION_GET_REF_EMPTY2
 cache: eviction calls to get a page found queue empty after locking
 
#define WT_STAT_CONN_CACHE_EVICTION_AGGRESSIVE_SET
 cache: eviction currently operating in aggressive mode
 
#define WT_STAT_CONN_CACHE_EVICTION_EMPTY_SCORE
 cache: eviction empty score
 
#define WT_STAT_CONN_CACHE_EVICTION_WALK_PASSES
 cache: eviction passes of a file
 
#define WT_STAT_CONN_CACHE_EVICTION_QUEUE_EMPTY
 cache: eviction server candidate queue empty when topping up
 
#define WT_STAT_CONN_CACHE_EVICTION_QUEUE_NOT_EMPTY
 cache: eviction server candidate queue not empty when topping up
 
#define WT_STAT_CONN_CACHE_EVICTION_SERVER_EVICTING
 cache: eviction server evicting pages
 
#define WT_STAT_CONN_CACHE_EVICTION_SERVER_SLEPT
 cache: eviction server slept, because we did not make progress with eviction
 
#define WT_STAT_CONN_CACHE_EVICTION_SLOW
 cache: eviction server unable to reach eviction goal
 
#define WT_STAT_CONN_CACHE_EVICTION_STATE
 cache: eviction state
 
#define WT_STAT_CONN_CACHE_EVICTION_TARGET_PAGE_LT10
 cache: eviction walk target pages histogram - 0-9
 
#define WT_STAT_CONN_CACHE_EVICTION_TARGET_PAGE_LT32
 cache: eviction walk target pages histogram - 10-31
 
#define WT_STAT_CONN_CACHE_EVICTION_TARGET_PAGE_GE128
 cache: eviction walk target pages histogram - 128 and higher
 
#define WT_STAT_CONN_CACHE_EVICTION_TARGET_PAGE_LT64
 cache: eviction walk target pages histogram - 32-63
 
#define WT_STAT_CONN_CACHE_EVICTION_TARGET_PAGE_LT128
 cache: eviction walk target pages histogram - 64-128
 
#define WT_STAT_CONN_CACHE_EVICTION_WALKS_ABANDONED
 cache: eviction walks abandoned
 
#define WT_STAT_CONN_CACHE_EVICTION_WALKS_STOPPED
 cache: eviction walks gave up because they restarted their walk twice
 
#define WT_STAT_CONN_CACHE_EVICTION_WALKS_GAVE_UP_NO_TARGETS
 cache: eviction walks gave up because they saw too many pages and found no candidates
 
#define WT_STAT_CONN_CACHE_EVICTION_WALKS_GAVE_UP_RATIO
 cache: eviction walks gave up because they saw too many pages and found too few candidates
 
#define WT_STAT_CONN_CACHE_EVICTION_WALKS_ENDED
 cache: eviction walks reached end of tree
 
#define WT_STAT_CONN_CACHE_EVICTION_WALK_FROM_ROOT
 cache: eviction walks started from root of tree
 
#define WT_STAT_CONN_CACHE_EVICTION_WALK_SAVED_POS
 cache: eviction walks started from saved location in tree
 
#define WT_STAT_CONN_CACHE_EVICTION_ACTIVE_WORKERS
 cache: eviction worker thread active
 
#define WT_STAT_CONN_CACHE_EVICTION_WORKER_CREATED
 cache: eviction worker thread created
 
#define WT_STAT_CONN_CACHE_EVICTION_WORKER_EVICTING
 cache: eviction worker thread evicting pages
 
#define WT_STAT_CONN_CACHE_EVICTION_WORKER_REMOVED
 cache: eviction worker thread removed
 
#define WT_STAT_CONN_CACHE_EVICTION_STABLE_STATE_WORKERS
 cache: eviction worker thread stable number
 
#define WT_STAT_CONN_CACHE_EVICTION_FORCE_FAIL
 cache: failed eviction of pages that exceeded the in-memory maximum count
 
#define WT_STAT_CONN_CACHE_EVICTION_FORCE_FAIL_TIME
 cache: failed eviction of pages that exceeded the in-memory maximum time (usecs)
 
#define WT_STAT_CONN_CACHE_EVICTION_WALKS_ACTIVE
 cache: files with active eviction walks
 
#define WT_STAT_CONN_CACHE_EVICTION_WALKS_STARTED
 cache: files with new eviction walks started
 
#define WT_STAT_CONN_CACHE_EVICTION_FORCE_RETUNE
 cache: force re-tuning of eviction workers once in a while
 
#define WT_STAT_CONN_CACHE_EVICTION_HAZARD
 cache: hazard pointer blocked page eviction
 
#define WT_STAT_CONN_CACHE_HAZARD_CHECKS
 cache: hazard pointer check calls
 
#define WT_STAT_CONN_CACHE_HAZARD_WALKS
 cache: hazard pointer check entries walked
 
#define WT_STAT_CONN_CACHE_HAZARD_MAX
 cache: hazard pointer maximum array length
 
#define WT_STAT_CONN_CACHE_INMEM_SPLITTABLE
 cache: in-memory page passed criteria to be split
 
#define WT_STAT_CONN_CACHE_INMEM_SPLIT
 cache: in-memory page splits
 
#define WT_STAT_CONN_CACHE_EVICTION_INTERNAL
 cache: internal pages evicted
 
#define WT_STAT_CONN_CACHE_EVICTION_SPLIT_INTERNAL
 cache: internal pages split during eviction
 
#define WT_STAT_CONN_CACHE_EVICTION_SPLIT_LEAF
 cache: leaf pages split during eviction
 
#define WT_STAT_CONN_CACHE_LOOKASIDE_INSERT
 cache: lookaside table insert calls
 
#define WT_STAT_CONN_CACHE_LOOKASIDE_REMOVE
 cache: lookaside table remove calls
 
#define WT_STAT_CONN_CACHE_BYTES_MAX
 cache: maximum bytes configured
 
#define WT_STAT_CONN_CACHE_EVICTION_MAXIMUM_PAGE_SIZE
 cache: maximum page size at eviction
 
#define WT_STAT_CONN_CACHE_EVICTION_DIRTY
 cache: modified pages evicted
 
#define WT_STAT_CONN_CACHE_EVICTION_APP_DIRTY
 cache: modified pages evicted by application threads
 
#define WT_STAT_CONN_CACHE_READ_OVERFLOW
 cache: overflow pages read into cache
 
#define WT_STAT_CONN_CACHE_EVICTION_DEEPEN
 cache: page split during eviction deepened the tree
 
#define WT_STAT_CONN_CACHE_WRITE_LOOKASIDE
 cache: page written requiring lookaside records
 
#define WT_STAT_CONN_CACHE_PAGES_INUSE
 cache: pages currently held in the cache
 
#define WT_STAT_CONN_CACHE_EVICTION_FORCE
 cache: pages evicted because they exceeded the in-memory maximum count
 
#define WT_STAT_CONN_CACHE_EVICTION_FORCE_TIME
 cache: pages evicted because they exceeded the in-memory maximum time (usecs)
 
#define WT_STAT_CONN_CACHE_EVICTION_FORCE_DELETE
 cache: pages evicted because they had chains of deleted items count
 
#define WT_STAT_CONN_CACHE_EVICTION_FORCE_DELETE_TIME
 cache: pages evicted because they had chains of deleted items time (usecs)
 
#define WT_STAT_CONN_CACHE_EVICTION_APP
 cache: pages evicted by application threads
 
#define WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED
 cache: pages queued for eviction
 
#define WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED_URGENT
 cache: pages queued for urgent eviction
 
#define WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED_OLDEST
 cache: pages queued for urgent eviction during walk
 
#define WT_STAT_CONN_CACHE_READ
 cache: pages read into cache
 
#define WT_STAT_CONN_CACHE_READ_LOOKASIDE
 cache: pages read into cache requiring lookaside entries
 
#define WT_STAT_CONN_CACHE_PAGES_REQUESTED
 cache: pages requested from the cache
 
#define WT_STAT_CONN_CACHE_EVICTION_PAGES_SEEN
 cache: pages seen by eviction walk
 
#define WT_STAT_CONN_CACHE_EVICTION_FAIL
 cache: pages selected for eviction unable to be evicted
 
#define WT_STAT_CONN_CACHE_EVICTION_WALK
 cache: pages walked for eviction
 
#define WT_STAT_CONN_CACHE_WRITE
 cache: pages written from cache
 
#define WT_STAT_CONN_CACHE_WRITE_RESTORE
 cache: pages written requiring in-memory restoration
 
#define WT_STAT_CONN_CACHE_OVERHEAD
 cache: percentage overhead
 
#define WT_STAT_CONN_CACHE_BYTES_INTERNAL
 cache: tracked bytes belonging to internal pages in the cache
 
#define WT_STAT_CONN_CACHE_BYTES_LEAF
 cache: tracked bytes belonging to leaf pages in the cache
 
#define WT_STAT_CONN_CACHE_BYTES_DIRTY
 cache: tracked dirty bytes in the cache
 
#define WT_STAT_CONN_CACHE_PAGES_DIRTY
 cache: tracked dirty pages in the cache
 
#define WT_STAT_CONN_CACHE_EVICTION_CLEAN
 cache: unmodified pages evicted
 
#define WT_STAT_CONN_COND_AUTO_WAIT_RESET
 connection: auto adjusting condition resets
 
#define WT_STAT_CONN_COND_AUTO_WAIT
 connection: auto adjusting condition wait calls
 
#define WT_STAT_CONN_TIME_TRAVEL
 connection: detected system time went backwards
 
#define WT_STAT_CONN_FILE_OPEN
 connection: files currently open
 
#define WT_STAT_CONN_MEMORY_ALLOCATION
 connection: memory allocations
 
#define WT_STAT_CONN_MEMORY_FREE
 connection: memory frees
 
#define WT_STAT_CONN_MEMORY_GROW
 connection: memory re-allocations
 
#define WT_STAT_CONN_COND_WAIT
 connection: pthread mutex condition wait calls
 
#define WT_STAT_CONN_RWLOCK_READ
 connection: pthread mutex shared lock read-lock calls
 
#define WT_STAT_CONN_RWLOCK_WRITE
 connection: pthread mutex shared lock write-lock calls
 
#define WT_STAT_CONN_FSYNC_IO
 connection: total fsync I/Os
 
#define WT_STAT_CONN_READ_IO
 connection: total read I/Os
 
#define WT_STAT_CONN_WRITE_IO
 connection: total write I/Os
 
#define WT_STAT_CONN_CURSOR_CREATE
 cursor: cursor create calls
 
#define WT_STAT_CONN_CURSOR_INSERT
 cursor: cursor insert calls
 
#define WT_STAT_CONN_CURSOR_MODIFY
 cursor: cursor modify calls
 
#define WT_STAT_CONN_CURSOR_NEXT
 cursor: cursor next calls
 
#define WT_STAT_CONN_CURSOR_PREV
 cursor: cursor prev calls
 
#define WT_STAT_CONN_CURSOR_REMOVE
 cursor: cursor remove calls
 
#define WT_STAT_CONN_CURSOR_RESERVE
 cursor: cursor reserve calls
 
#define WT_STAT_CONN_CURSOR_RESET
 cursor: cursor reset calls
 
#define WT_STAT_CONN_CURSOR_RESTART
 cursor: cursor restarted searches
 
#define WT_STAT_CONN_CURSOR_SEARCH
 cursor: cursor search calls
 
#define WT_STAT_CONN_CURSOR_SEARCH_NEAR
 cursor: cursor search near calls
 
#define WT_STAT_CONN_CURSOR_UPDATE
 cursor: cursor update calls
 
#define WT_STAT_CONN_CURSOR_TRUNCATE
 cursor: truncate calls
 
#define WT_STAT_CONN_DH_CONN_HANDLE_COUNT
 data-handle: connection data handles currently active
 
#define WT_STAT_CONN_DH_SWEEP_REF
 data-handle: connection sweep candidate became referenced
 
#define WT_STAT_CONN_DH_SWEEP_CLOSE
 data-handle: connection sweep dhandles closed
 
#define WT_STAT_CONN_DH_SWEEP_REMOVE
 data-handle: connection sweep dhandles removed from hash list
 
#define WT_STAT_CONN_DH_SWEEP_TOD
 data-handle: connection sweep time-of-death sets
 
#define WT_STAT_CONN_DH_SWEEPS
 data-handle: connection sweeps
 
#define WT_STAT_CONN_DH_SESSION_HANDLES
 data-handle: session dhandles swept
 
#define WT_STAT_CONN_DH_SESSION_SWEEPS
 data-handle: session sweep attempts
 
#define WT_STAT_CONN_LOCK_CHECKPOINT_COUNT
 lock: checkpoint lock acquisitions
 
#define WT_STAT_CONN_LOCK_CHECKPOINT_WAIT_APPLICATION
 lock: checkpoint lock application thread wait time (usecs)
 
#define WT_STAT_CONN_LOCK_CHECKPOINT_WAIT_INTERNAL
 lock: checkpoint lock internal thread wait time (usecs)
 
#define WT_STAT_CONN_LOCK_DHANDLE_WAIT_APPLICATION
 lock: dhandle lock application thread time waiting for the dhandle lock (usecs)
 
#define WT_STAT_CONN_LOCK_DHANDLE_WAIT_INTERNAL
 lock: dhandle lock internal thread time waiting for the dhandle lock (usecs)
 
#define WT_STAT_CONN_LOCK_DHANDLE_READ_COUNT
 lock: dhandle read lock acquisitions
 
#define WT_STAT_CONN_LOCK_DHANDLE_WRITE_COUNT
 lock: dhandle write lock acquisitions
 
#define WT_STAT_CONN_LOCK_METADATA_COUNT
 lock: metadata lock acquisitions
 
#define WT_STAT_CONN_LOCK_METADATA_WAIT_APPLICATION
 lock: metadata lock application thread wait time (usecs)
 
#define WT_STAT_CONN_LOCK_METADATA_WAIT_INTERNAL
 lock: metadata lock internal thread wait time (usecs)
 
#define WT_STAT_CONN_LOCK_SCHEMA_COUNT
 lock: schema lock acquisitions
 
#define WT_STAT_CONN_LOCK_SCHEMA_WAIT_APPLICATION
 lock: schema lock application thread wait time (usecs)
 
#define WT_STAT_CONN_LOCK_SCHEMA_WAIT_INTERNAL
 lock: schema lock internal thread wait time (usecs)
 
#define WT_STAT_CONN_LOCK_TABLE_WAIT_APPLICATION
 lock: table lock application thread time waiting for the table lock (usecs)
 
#define WT_STAT_CONN_LOCK_TABLE_WAIT_INTERNAL
 lock: table lock internal thread time waiting for the table lock (usecs)
 
#define WT_STAT_CONN_LOCK_TABLE_READ_COUNT
 lock: table read lock acquisitions
 
#define WT_STAT_CONN_LOCK_TABLE_WRITE_COUNT
 lock: table write lock acquisitions
 
#define WT_STAT_CONN_LOG_SLOT_SWITCH_BUSY
 log: busy returns attempting to switch slots
 
#define WT_STAT_CONN_LOG_FORCE_CKPT_SLEEP
 log: force checkpoint calls slept
 
#define WT_STAT_CONN_LOG_BYTES_PAYLOAD
 log: log bytes of payload data
 
#define WT_STAT_CONN_LOG_BYTES_WRITTEN
 log: log bytes written
 
#define WT_STAT_CONN_LOG_ZERO_FILLS
 log: log files manually zero-filled
 
#define WT_STAT_CONN_LOG_FLUSH
 log: log flush operations
 
#define WT_STAT_CONN_LOG_FORCE_WRITE
 log: log force write operations
 
#define WT_STAT_CONN_LOG_FORCE_WRITE_SKIP
 log: log force write operations skipped
 
#define WT_STAT_CONN_LOG_COMPRESS_WRITES
 log: log records compressed
 
#define WT_STAT_CONN_LOG_COMPRESS_WRITE_FAILS
 log: log records not compressed
 
#define WT_STAT_CONN_LOG_COMPRESS_SMALL
 log: log records too small to compress
 
#define WT_STAT_CONN_LOG_RELEASE_WRITE_LSN
 log: log release advances write LSN
 
#define WT_STAT_CONN_LOG_SCANS
 log: log scan operations
 
#define WT_STAT_CONN_LOG_SCAN_REREADS
 log: log scan records requiring two reads
 
#define WT_STAT_CONN_LOG_WRITE_LSN
 log: log server thread advances write LSN
 
#define WT_STAT_CONN_LOG_WRITE_LSN_SKIP
 log: log server thread write LSN walk skipped
 
#define WT_STAT_CONN_LOG_SYNC
 log: log sync operations
 
#define WT_STAT_CONN_LOG_SYNC_DURATION
 log: log sync time duration (usecs)
 
#define WT_STAT_CONN_LOG_SYNC_DIR
 log: log sync_dir operations
 
#define WT_STAT_CONN_LOG_SYNC_DIR_DURATION
 log: log sync_dir time duration (usecs)
 
#define WT_STAT_CONN_LOG_WRITES
 log: log write operations
 
#define WT_STAT_CONN_LOG_SLOT_CONSOLIDATED
 log: logging bytes consolidated
 
#define WT_STAT_CONN_LOG_MAX_FILESIZE
 log: maximum log file size
 
#define WT_STAT_CONN_LOG_PREALLOC_MAX
 log: number of pre-allocated log files to create
 
#define WT_STAT_CONN_LOG_PREALLOC_MISSED
 log: pre-allocated log files not ready and missed
 
#define WT_STAT_CONN_LOG_PREALLOC_FILES
 log: pre-allocated log files prepared
 
#define WT_STAT_CONN_LOG_PREALLOC_USED
 log: pre-allocated log files used
 
#define WT_STAT_CONN_LOG_SCAN_RECORDS
 log: records processed by log scan
 
#define WT_STAT_CONN_LOG_SLOT_CLOSE_RACE
 log: slot close lost race
 
#define WT_STAT_CONN_LOG_SLOT_CLOSE_UNBUF
 log: slot close unbuffered waits
 
#define WT_STAT_CONN_LOG_SLOT_CLOSES
 log: slot closures
 
#define WT_STAT_CONN_LOG_SLOT_RACES
 log: slot join atomic update races
 
#define WT_STAT_CONN_LOG_SLOT_YIELD_RACE
 log: slot join calls atomic updates raced
 
#define WT_STAT_CONN_LOG_SLOT_IMMEDIATE
 log: slot join calls did not yield
 
#define WT_STAT_CONN_LOG_SLOT_YIELD_CLOSE
 log: slot join calls found active slot closed
 
#define WT_STAT_CONN_LOG_SLOT_YIELD_SLEEP
 log: slot join calls slept
 
#define WT_STAT_CONN_LOG_SLOT_YIELD
 log: slot join calls yielded
 
#define WT_STAT_CONN_LOG_SLOT_ACTIVE_CLOSED
 log: slot join found active slot closed
 
#define WT_STAT_CONN_LOG_SLOT_YIELD_DURATION
 log: slot joins yield time (usecs)
 
#define WT_STAT_CONN_LOG_SLOT_NO_FREE_SLOTS
 log: slot transitions unable to find free slot
 
#define WT_STAT_CONN_LOG_SLOT_UNBUFFERED
 log: slot unbuffered writes
 
#define WT_STAT_CONN_LOG_COMPRESS_MEM
 log: total in-memory size of compressed records
 
#define WT_STAT_CONN_LOG_BUFFER_SIZE
 log: total log buffer size
 
#define WT_STAT_CONN_LOG_COMPRESS_LEN
 log: total size of compressed records
 
#define WT_STAT_CONN_LOG_SLOT_COALESCED
 log: written slots coalesced
 
#define WT_STAT_CONN_LOG_CLOSE_YIELDS
 log: yields waiting for previous log file close
 
#define WT_STAT_CONN_REC_PAGE_DELETE_FAST
 reconciliation: fast-path pages deleted
 
#define WT_STAT_CONN_REC_PAGES
 reconciliation: page reconciliation calls
 
#define WT_STAT_CONN_REC_PAGES_EVICTION
 reconciliation: page reconciliation calls for eviction
 
#define WT_STAT_CONN_REC_PAGE_DELETE
 reconciliation: pages deleted
 
#define WT_STAT_CONN_REC_SPLIT_STASHED_BYTES
 reconciliation: split bytes currently awaiting free
 
#define WT_STAT_CONN_REC_SPLIT_STASHED_OBJECTS
 reconciliation: split objects currently awaiting free
 
#define WT_STAT_CONN_SESSION_CURSOR_OPEN
 session: open cursor count
 
#define WT_STAT_CONN_SESSION_OPEN
 session: open session count
 
#define WT_STAT_CONN_SESSION_TABLE_ALTER_FAIL
 session: table alter failed calls
 
#define WT_STAT_CONN_SESSION_TABLE_ALTER_SUCCESS
 session: table alter successful calls
 
#define WT_STAT_CONN_SESSION_TABLE_ALTER_SKIP
 session: table alter unchanged and skipped
 
#define WT_STAT_CONN_SESSION_TABLE_COMPACT_FAIL
 session: table compact failed calls
 
#define WT_STAT_CONN_SESSION_TABLE_COMPACT_SUCCESS
 session: table compact successful calls
 
#define WT_STAT_CONN_SESSION_TABLE_CREATE_FAIL
 session: table create failed calls
 
#define WT_STAT_CONN_SESSION_TABLE_CREATE_SUCCESS
 session: table create successful calls
 
#define WT_STAT_CONN_SESSION_TABLE_DROP_FAIL
 session: table drop failed calls
 
#define WT_STAT_CONN_SESSION_TABLE_DROP_SUCCESS
 session: table drop successful calls
 
#define WT_STAT_CONN_SESSION_TABLE_REBALANCE_FAIL
 session: table rebalance failed calls
 
#define WT_STAT_CONN_SESSION_TABLE_REBALANCE_SUCCESS
 session: table rebalance successful calls
 
#define WT_STAT_CONN_SESSION_TABLE_RENAME_FAIL
 session: table rename failed calls
 
#define WT_STAT_CONN_SESSION_TABLE_RENAME_SUCCESS
 session: table rename successful calls
 
#define WT_STAT_CONN_SESSION_TABLE_SALVAGE_FAIL
 session: table salvage failed calls
 
#define WT_STAT_CONN_SESSION_TABLE_SALVAGE_SUCCESS
 session: table salvage successful calls
 
#define WT_STAT_CONN_SESSION_TABLE_TRUNCATE_FAIL
 session: table truncate failed calls
 
#define WT_STAT_CONN_SESSION_TABLE_TRUNCATE_SUCCESS
 session: table truncate successful calls
 
#define WT_STAT_CONN_SESSION_TABLE_VERIFY_FAIL
 session: table verify failed calls
 
#define WT_STAT_CONN_SESSION_TABLE_VERIFY_SUCCESS
 session: table verify successful calls
 
#define WT_STAT_CONN_THREAD_FSYNC_ACTIVE
 thread-state: active filesystem fsync calls
 
#define WT_STAT_CONN_THREAD_READ_ACTIVE
 thread-state: active filesystem read calls
 
#define WT_STAT_CONN_THREAD_WRITE_ACTIVE
 thread-state: active filesystem write calls
 
#define WT_STAT_CONN_APPLICATION_EVICT_TIME
 thread-yield: application thread time evicting (usecs)
 
#define WT_STAT_CONN_APPLICATION_CACHE_TIME
 thread-yield: application thread time waiting for cache (usecs)
 
#define WT_STAT_CONN_TXN_RELEASE_BLOCKED
 thread-yield: connection close blocked waiting for transaction state stabilization
 
#define WT_STAT_CONN_CONN_CLOSE_BLOCKED_LSM
 thread-yield: connection close yielded for lsm manager shutdown
 
#define WT_STAT_CONN_DHANDLE_LOCK_BLOCKED
 thread-yield: data handle lock yielded
 
#define WT_STAT_CONN_PAGE_INDEX_SLOT_REF_BLOCKED
 thread-yield: get reference for page index and slot time sleeping (usecs)
 
#define WT_STAT_CONN_LOG_SERVER_SYNC_BLOCKED
 thread-yield: log server sync yielded for log write
 
#define WT_STAT_CONN_PAGE_BUSY_BLOCKED
 thread-yield: page acquire busy blocked
 
#define WT_STAT_CONN_PAGE_FORCIBLE_EVICT_BLOCKED
 thread-yield: page acquire eviction blocked
 
#define WT_STAT_CONN_PAGE_LOCKED_BLOCKED
 thread-yield: page acquire locked blocked
 
#define WT_STAT_CONN_PAGE_READ_BLOCKED
 thread-yield: page acquire read blocked
 
#define WT_STAT_CONN_PAGE_SLEEP
 thread-yield: page acquire time sleeping (usecs)
 
#define WT_STAT_CONN_PAGE_DEL_ROLLBACK_BLOCKED
 thread-yield: page delete rollback time sleeping for state change (usecs)
 
#define WT_STAT_CONN_CHILD_MODIFY_BLOCKED_PAGE
 thread-yield: page reconciliation yielded due to child modification
 
#define WT_STAT_CONN_TREE_DESCEND_BLOCKED
 thread-yield: tree descend one level yielded for split page index update
 
#define WT_STAT_CONN_TXN_SNAPSHOTS_CREATED
 transaction: number of named snapshots created
 
#define WT_STAT_CONN_TXN_SNAPSHOTS_DROPPED
 transaction: number of named snapshots dropped
 
#define WT_STAT_CONN_TXN_BEGIN
 transaction: transaction begins
 
#define WT_STAT_CONN_TXN_CHECKPOINT_RUNNING
 transaction: transaction checkpoint currently running
 
#define WT_STAT_CONN_TXN_CHECKPOINT_GENERATION
 transaction: transaction checkpoint generation
 
#define WT_STAT_CONN_TXN_CHECKPOINT_TIME_MAX
 transaction: transaction checkpoint max time (msecs)
 
#define WT_STAT_CONN_TXN_CHECKPOINT_TIME_MIN
 transaction: transaction checkpoint min time (msecs)
 
#define WT_STAT_CONN_TXN_CHECKPOINT_TIME_RECENT
 transaction: transaction checkpoint most recent time (msecs)
 
#define WT_STAT_CONN_TXN_CHECKPOINT_SCRUB_TARGET
 transaction: transaction checkpoint scrub dirty target
 
#define WT_STAT_CONN_TXN_CHECKPOINT_SCRUB_TIME
 transaction: transaction checkpoint scrub time (msecs)
 
#define WT_STAT_CONN_TXN_CHECKPOINT_TIME_TOTAL
 transaction: transaction checkpoint total time (msecs)
 
#define WT_STAT_CONN_TXN_CHECKPOINT
 transaction: transaction checkpoints
 
#define WT_STAT_CONN_TXN_CHECKPOINT_SKIPPED
 transaction: transaction checkpoints skipped because database was clean
 
#define WT_STAT_CONN_TXN_FAIL_CACHE
 transaction: transaction failures due to cache overflow
 
#define WT_STAT_CONN_TXN_CHECKPOINT_FSYNC_POST
 transaction: transaction fsync calls for checkpoint after allocating the transaction ID
 
#define WT_STAT_CONN_TXN_CHECKPOINT_FSYNC_POST_DURATION
 transaction: transaction fsync duration for checkpoint after allocating the transaction ID (usecs)
 
#define WT_STAT_CONN_TXN_PINNED_RANGE
 transaction: transaction range of IDs currently pinned
 
#define WT_STAT_CONN_TXN_PINNED_CHECKPOINT_RANGE
 transaction: transaction range of IDs currently pinned by a checkpoint
 
#define WT_STAT_CONN_TXN_PINNED_SNAPSHOT_RANGE
 transaction: transaction range of IDs currently pinned by named snapshots
 
#define WT_STAT_CONN_TXN_SYNC
 transaction: transaction sync calls
 
#define WT_STAT_CONN_TXN_COMMIT
 transaction: transactions committed
 
#define WT_STAT_CONN_TXN_ROLLBACK
 transaction: transactions rolled back
 
#define WT_STAT_CONN_TXN_UPDATE_CONFLICT
 transaction: update conflicts
 

Statistics for data sources

#define WT_STAT_DSRC_BLOOM_FALSE_POSITIVE
 LSM: bloom filter false positives.
 
#define WT_STAT_DSRC_BLOOM_HIT
 LSM: bloom filter hits.
 
#define WT_STAT_DSRC_BLOOM_MISS
 LSM: bloom filter misses.
 
#define WT_STAT_DSRC_BLOOM_PAGE_EVICT
 LSM: bloom filter pages evicted from cache.
 
#define WT_STAT_DSRC_BLOOM_PAGE_READ
 LSM: bloom filter pages read into cache.
 
#define WT_STAT_DSRC_BLOOM_COUNT
 LSM: bloom filters in the LSM tree.
 
#define WT_STAT_DSRC_LSM_CHUNK_COUNT
 LSM: chunks in the LSM tree.
 
#define WT_STAT_DSRC_LSM_GENERATION_MAX
 LSM: highest merge generation in the LSM tree.
 
#define WT_STAT_DSRC_LSM_LOOKUP_NO_BLOOM
 LSM: queries that could have benefited from a Bloom filter that did not exist.
 
#define WT_STAT_DSRC_LSM_CHECKPOINT_THROTTLE
 LSM: sleep for LSM checkpoint throttle.
 
#define WT_STAT_DSRC_LSM_MERGE_THROTTLE
 LSM: sleep for LSM merge throttle.
 
#define WT_STAT_DSRC_BLOOM_SIZE
 LSM: total size of bloom filters.
 
#define WT_STAT_DSRC_BLOCK_EXTENSION
 block-manager: allocations requiring file extension
 
#define WT_STAT_DSRC_BLOCK_ALLOC
 block-manager: blocks allocated
 
#define WT_STAT_DSRC_BLOCK_FREE
 block-manager: blocks freed
 
#define WT_STAT_DSRC_BLOCK_CHECKPOINT_SIZE
 block-manager: checkpoint size
 
#define WT_STAT_DSRC_ALLOCATION_SIZE
 block-manager: file allocation unit size
 
#define WT_STAT_DSRC_BLOCK_REUSE_BYTES
 block-manager: file bytes available for reuse
 
#define WT_STAT_DSRC_BLOCK_MAGIC
 block-manager: file magic number
 
#define WT_STAT_DSRC_BLOCK_MAJOR
 block-manager: file major version number
 
#define WT_STAT_DSRC_BLOCK_SIZE
 block-manager: file size in bytes
 
#define WT_STAT_DSRC_BLOCK_MINOR
 block-manager: minor version number
 
#define WT_STAT_DSRC_BTREE_CHECKPOINT_GENERATION
 btree: btree checkpoint generation
 
#define WT_STAT_DSRC_BTREE_COLUMN_FIX
 btree: column-store fixed-size leaf pages, only reported if tree_walk or all statistics are enabled
 
#define WT_STAT_DSRC_BTREE_COLUMN_INTERNAL
 btree: column-store internal pages, only reported if tree_walk or all statistics are enabled
 
#define WT_STAT_DSRC_BTREE_COLUMN_RLE
 btree: column-store variable-size RLE encoded values, only reported if tree_walk or all statistics are enabled
 
#define WT_STAT_DSRC_BTREE_COLUMN_DELETED
 btree: column-store variable-size deleted values, only reported if tree_walk or all statistics are enabled
 
#define WT_STAT_DSRC_BTREE_COLUMN_VARIABLE
 btree: column-store variable-size leaf pages, only reported if tree_walk or all statistics are enabled
 
#define WT_STAT_DSRC_BTREE_FIXED_LEN
 btree: fixed-record size
 
#define WT_STAT_DSRC_BTREE_MAXINTLKEY
 btree: maximum internal page key size
 
#define WT_STAT_DSRC_BTREE_MAXINTLPAGE
 btree: maximum internal page size
 
#define WT_STAT_DSRC_BTREE_MAXLEAFKEY
 btree: maximum leaf page key size
 
#define WT_STAT_DSRC_BTREE_MAXLEAFPAGE
 btree: maximum leaf page size
 
#define WT_STAT_DSRC_BTREE_MAXLEAFVALUE
 btree: maximum leaf page value size
 
#define WT_STAT_DSRC_BTREE_MAXIMUM_DEPTH
 btree: maximum tree depth
 
#define WT_STAT_DSRC_BTREE_ENTRIES
 btree: number of key/value pairs, only reported if tree_walk or all statistics are enabled
 
#define WT_STAT_DSRC_BTREE_OVERFLOW
 btree: overflow pages, only reported if tree_walk or all statistics are enabled
 
#define WT_STAT_DSRC_BTREE_COMPACT_REWRITE
 btree: pages rewritten by compaction
 
#define WT_STAT_DSRC_BTREE_ROW_INTERNAL
 btree: row-store internal pages, only reported if tree_walk or all statistics are enabled
 
#define WT_STAT_DSRC_BTREE_ROW_LEAF
 btree: row-store leaf pages, only reported if tree_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_BYTES_INUSE
 cache: bytes currently in the cache
 
#define WT_STAT_DSRC_CACHE_BYTES_READ
 cache: bytes read into cache
 
#define WT_STAT_DSRC_CACHE_BYTES_WRITE
 cache: bytes written from cache
 
#define WT_STAT_DSRC_CACHE_EVICTION_CHECKPOINT
 cache: checkpoint blocked page eviction
 
#define WT_STAT_DSRC_CACHE_EVICTION_FAIL
 cache: data source pages selected for eviction unable to be evicted
 
#define WT_STAT_DSRC_CACHE_EVICTION_WALK_PASSES
 cache: eviction walk passes of a file
 
#define WT_STAT_DSRC_CACHE_EVICTION_TARGET_PAGE_LT10
 cache: eviction walk target pages histogram - 0-9
 
#define WT_STAT_DSRC_CACHE_EVICTION_TARGET_PAGE_LT32
 cache: eviction walk target pages histogram - 10-31
 
#define WT_STAT_DSRC_CACHE_EVICTION_TARGET_PAGE_GE128
 cache: eviction walk target pages histogram - 128 and higher
 
#define WT_STAT_DSRC_CACHE_EVICTION_TARGET_PAGE_LT64
 cache: eviction walk target pages histogram - 32-63
 
#define WT_STAT_DSRC_CACHE_EVICTION_TARGET_PAGE_LT128
 cache: eviction walk target pages histogram - 64-128
 
#define WT_STAT_DSRC_CACHE_EVICTION_WALKS_ABANDONED
 cache: eviction walks abandoned
 
#define WT_STAT_DSRC_CACHE_EVICTION_WALKS_STOPPED
 cache: eviction walks gave up because they restarted their walk twice
 
#define WT_STAT_DSRC_CACHE_EVICTION_WALKS_GAVE_UP_NO_TARGETS
 cache: eviction walks gave up because they saw too many pages and found no candidates
 
#define WT_STAT_DSRC_CACHE_EVICTION_WALKS_GAVE_UP_RATIO
 cache: eviction walks gave up because they saw too many pages and found too few candidates
 
#define WT_STAT_DSRC_CACHE_EVICTION_WALKS_ENDED
 cache: eviction walks reached end of tree
 
#define WT_STAT_DSRC_CACHE_EVICTION_WALK_FROM_ROOT
 cache: eviction walks started from root of tree
 
#define WT_STAT_DSRC_CACHE_EVICTION_WALK_SAVED_POS
 cache: eviction walks started from saved location in tree
 
#define WT_STAT_DSRC_CACHE_EVICTION_HAZARD
 cache: hazard pointer blocked page eviction
 
#define WT_STAT_DSRC_CACHE_INMEM_SPLITTABLE
 cache: in-memory page passed criteria to be split
 
#define WT_STAT_DSRC_CACHE_INMEM_SPLIT
 cache: in-memory page splits
 
#define WT_STAT_DSRC_CACHE_EVICTION_INTERNAL
 cache: internal pages evicted
 
#define WT_STAT_DSRC_CACHE_EVICTION_SPLIT_INTERNAL
 cache: internal pages split during eviction
 
#define WT_STAT_DSRC_CACHE_EVICTION_SPLIT_LEAF
 cache: leaf pages split during eviction
 
#define WT_STAT_DSRC_CACHE_EVICTION_DIRTY
 cache: modified pages evicted
 
#define WT_STAT_DSRC_CACHE_READ_OVERFLOW
 cache: overflow pages read into cache
 
#define WT_STAT_DSRC_CACHE_EVICTION_DEEPEN
 cache: page split during eviction deepened the tree
 
#define WT_STAT_DSRC_CACHE_WRITE_LOOKASIDE
 cache: page written requiring lookaside records
 
#define WT_STAT_DSRC_CACHE_READ
 cache: pages read into cache
 
#define WT_STAT_DSRC_CACHE_READ_LOOKASIDE
 cache: pages read into cache requiring lookaside entries
 
#define WT_STAT_DSRC_CACHE_PAGES_REQUESTED
 cache: pages requested from the cache
 
#define WT_STAT_DSRC_CACHE_EVICTION_PAGES_SEEN
 cache: pages seen by eviction walk
 
#define WT_STAT_DSRC_CACHE_WRITE
 cache: pages written from cache
 
#define WT_STAT_DSRC_CACHE_WRITE_RESTORE
 cache: pages written requiring in-memory restoration
 
#define WT_STAT_DSRC_CACHE_BYTES_DIRTY
 cache: tracked dirty bytes in the cache
 
#define WT_STAT_DSRC_CACHE_EVICTION_CLEAN
 cache: unmodified pages evicted
 
#define WT_STAT_DSRC_CACHE_STATE_GEN_AVG_GAP
 cache_walk: Average difference between current eviction generation when the page was last considered, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_AVG_WRITTEN_SIZE
 cache_walk: Average on-disk page image size seen, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_AVG_VISITED_AGE
 cache_walk: Average time in cache for pages that have been visited by the eviction server, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_AVG_UNVISITED_AGE
 cache_walk: Average time in cache for pages that have not been visited by the eviction server, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_PAGES_CLEAN
 cache_walk: Clean pages currently in cache, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_GEN_CURRENT
 cache_walk: Current eviction generation, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_PAGES_DIRTY
 cache_walk: Dirty pages currently in cache, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_ROOT_ENTRIES
 cache_walk: Entries in the root page, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_PAGES_INTERNAL
 cache_walk: Internal pages currently in cache, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_PAGES_LEAF
 cache_walk: Leaf pages currently in cache, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_GEN_MAX_GAP
 cache_walk: Maximum difference between current eviction generation when the page was last considered, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_MAX_PAGESIZE
 cache_walk: Maximum page size seen, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_MIN_WRITTEN_SIZE
 cache_walk: Minimum on-disk page image size seen, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_UNVISITED_COUNT
 cache_walk: Number of pages never visited by eviction server, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_SMALLER_ALLOC_SIZE
 cache_walk: On-disk page image sizes smaller than a single allocation unit, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_MEMORY
 cache_walk: Pages created in memory and never written, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_QUEUED
 cache_walk: Pages currently queued for eviction, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_NOT_QUEUEABLE
 cache_walk: Pages that could not be queued for eviction, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_REFS_SKIPPED
 cache_walk: Refs skipped during cache traversal, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_ROOT_SIZE
 cache_walk: Size of the root page, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_CACHE_STATE_PAGES
 cache_walk: Total number of pages currently in cache, only reported if cache_walk or all statistics are enabled
 
#define WT_STAT_DSRC_COMPRESS_READ
 compression: compressed pages read
 
#define WT_STAT_DSRC_COMPRESS_WRITE
 compression: compressed pages written
 
#define WT_STAT_DSRC_COMPRESS_WRITE_FAIL
 compression: page written failed to compress
 
#define WT_STAT_DSRC_COMPRESS_WRITE_TOO_SMALL
 compression: page written was too small to compress
 
#define WT_STAT_DSRC_COMPRESS_RAW_FAIL_TEMPORARY
 compression: raw compression call failed, additional data available
 
#define WT_STAT_DSRC_COMPRESS_RAW_FAIL
 compression: raw compression call failed, no additional data available
 
#define WT_STAT_DSRC_COMPRESS_RAW_OK
 compression: raw compression call succeeded
 
#define WT_STAT_DSRC_CURSOR_INSERT_BULK
 cursor: bulk-loaded cursor-insert calls
 
#define WT_STAT_DSRC_CURSOR_CREATE
 cursor: create calls
 
#define WT_STAT_DSRC_CURSOR_INSERT_BYTES
 cursor: cursor-insert key and value bytes inserted
 
#define WT_STAT_DSRC_CURSOR_REMOVE_BYTES
 cursor: cursor-remove key bytes removed
 
#define WT_STAT_DSRC_CURSOR_UPDATE_BYTES
 cursor: cursor-update value bytes updated
 
#define WT_STAT_DSRC_CURSOR_INSERT
 cursor: insert calls
 
#define WT_STAT_DSRC_CURSOR_MODIFY
 cursor: modify calls
 
#define WT_STAT_DSRC_CURSOR_NEXT
 cursor: next calls
 
#define WT_STAT_DSRC_CURSOR_PREV
 cursor: prev calls
 
#define WT_STAT_DSRC_CURSOR_REMOVE
 cursor: remove calls
 
#define WT_STAT_DSRC_CURSOR_RESERVE
 cursor: reserve calls
 
#define WT_STAT_DSRC_CURSOR_RESET
 cursor: reset calls
 
#define WT_STAT_DSRC_CURSOR_RESTART
 cursor: restarted searches
 
#define WT_STAT_DSRC_CURSOR_SEARCH
 cursor: search calls
 
#define WT_STAT_DSRC_CURSOR_SEARCH_NEAR
 cursor: search near calls
 
#define WT_STAT_DSRC_CURSOR_TRUNCATE
 cursor: truncate calls
 
#define WT_STAT_DSRC_CURSOR_UPDATE
 cursor: update calls
 
#define WT_STAT_DSRC_REC_DICTIONARY
 reconciliation: dictionary matches
 
#define WT_STAT_DSRC_REC_PAGE_DELETE_FAST
 reconciliation: fast-path pages deleted
 
#define WT_STAT_DSRC_REC_SUFFIX_COMPRESSION
 reconciliation: internal page key bytes discarded using suffix compression
 
#define WT_STAT_DSRC_REC_MULTIBLOCK_INTERNAL
 reconciliation: internal page multi-block writes
 
#define WT_STAT_DSRC_REC_OVERFLOW_KEY_INTERNAL
 reconciliation: internal-page overflow keys
 
#define WT_STAT_DSRC_REC_PREFIX_COMPRESSION
 reconciliation: leaf page key bytes discarded using prefix compression
 
#define WT_STAT_DSRC_REC_MULTIBLOCK_LEAF
 reconciliation: leaf page multi-block writes
 
#define WT_STAT_DSRC_REC_OVERFLOW_KEY_LEAF
 reconciliation: leaf-page overflow keys
 
#define WT_STAT_DSRC_REC_MULTIBLOCK_MAX
 reconciliation: maximum blocks required for a page
 
#define WT_STAT_DSRC_REC_OVERFLOW_VALUE
 reconciliation: overflow values written
 
#define WT_STAT_DSRC_REC_PAGE_MATCH
 reconciliation: page checksum matches
 
#define WT_STAT_DSRC_REC_PAGES
 reconciliation: page reconciliation calls
 
#define WT_STAT_DSRC_REC_PAGES_EVICTION
 reconciliation: page reconciliation calls for eviction
 
#define WT_STAT_DSRC_REC_PAGE_DELETE
 reconciliation: pages deleted
 
#define WT_STAT_DSRC_SESSION_COMPACT
 session: object compaction
 
#define WT_STAT_DSRC_SESSION_CURSOR_OPEN
 session: open cursor count
 
#define WT_STAT_DSRC_TXN_UPDATE_CONFLICT
 transaction: update conflicts
 

Statistics for join cursors

#define WT_STAT_JOIN_MAIN_ACCESS
 : accesses to the main table
 
#define WT_STAT_JOIN_BLOOM_FALSE_POSITIVE
 : bloom filter false positives
 
#define WT_STAT_JOIN_MEMBERSHIP_CHECK
 : checks that conditions of membership are satisfied
 
#define WT_STAT_JOIN_BLOOM_INSERT
 : items inserted into a bloom filter
 
#define WT_STAT_JOIN_ITERATED
 : items iterated
 

Detailed Description

The functions, handles and methods applications use to access and manage data with WiredTiger.


Class Documentation

struct WT_ITEM

A raw item of data to be managed, including a pointer to the data and a length.

WT_ITEM structures do not need to be cleared before use.

Examples:
ex_async.c, ex_encrypt.c, ex_extending.c, ex_extractor.c, ex_log.c, and ex_schema.c.
Class Members
const void * data The memory reference of the data item.

For items returned by a WT_CURSOR, the pointer is only valid until the next operation on that cursor. Applications that need to keep an item across multiple cursor operations must make a copy.

size_t size The number of bytes in the data item.

The maximum length of a single column stored in a table is not fixed (as it partially depends on the underlying file configuration), but is always a small number of bytes less than 4GB.

struct WT_MODIFY

A set of modifications for a value, including a pointer to new data and a length, plus a target offset in the value and an optional length of data in the value to be replaced.

WT_MODIFY structures do not need to be cleared before use.

Class Members
WT_ITEM data New data.

The size of the new data may be zero when no new data is provided.

size_t offset The zero-based byte offset in the value where the new data is placed.

If the offset is past the end of the value, nul bytes are appended to the value up to the specified offset.

size_t size The number of bytes in the value to be replaced.

If the size is zero, no bytes from the value are replaced and the new data is inserted.

If the offset is past the end of the value, the size is ignored.

If the offset plus the size overlaps the end of the previous value, bytes from the offset to the end of the value are replaced and any remaining new data is appended.

struct WT_CONFIG_ITEM

The configuration information returned by the WiredTiger configuration parsing functions in the WT_EXTENSION_API and the public API.

Examples:
ex_encrypt.c, ex_file_system.c, and rotn_encrypt.c.
Class Members
__unnamed__ Permitted values of the type field.
Class Members
size_t len The number of bytes in the value referenced by str.
const char * str The value of a configuration string.

Regardless of the type of the configuration string (boolean, int, list or string), the str field will reference the value of the configuration string.

The bytes referenced by str are not nul-terminated, use the len field instead of a terminating nul byte.

enum WT_CONFIG_ITEM type Permitted values of the type field.

The type of value determined by the parser. In all cases, the str and len fields are set.

int64_t val The numeric value of a configuration boolean or integer.

If the configuration string's value is "true" or "false", the val field will be set to 1 (true), or 0 (false).

If the configuration string can be legally interpreted as an integer, using the strtoll function rules as specified in ISO/IEC 9899:1990 ("ISO C90"), that integer will be stored in the val field.

Macro Definition Documentation

#define WT_CACHE_FULL

Operation would overflow cache.

This error is only generated when wiredtiger_open is configured to run in- memory, and an insert or update operation requires more than the configured cache size to complete. The operation may be retried; if a transaction is in progress, it should be rolled back and the operation retried in a new transaction.

#define WT_DUPLICATE_KEY

Attempt to insert an existing key.

This error is generated when the application attempts to insert a record with the same key as an existing record without the 'overwrite' configuration to WT_SESSION::open_cursor.

#define WT_ERROR

Non-specific WiredTiger error.

This error is returned when an error is not covered by a specific error return.

#define WT_INTPACK32_MAXSIZE

The maximum packed size of a 32-bit integer.

The wiredtiger_struct_pack function will pack single integers into at most this many bytes.

#define WT_INTPACK64_MAXSIZE

The maximum packed size of a 64-bit integer.

The wiredtiger_struct_pack function will pack single long integers into at most this many bytes.

#define WT_NOTFOUND

Item not found.

This error indicates an operation did not find a value to return. This includes cursor search and other operations where no record matched the cursor's search key such as WT_CURSOR::update or WT_CURSOR::remove.

Examples:
ex_access.c, ex_cursor.c, ex_encrypt.c, ex_extractor.c, ex_file_system.c, ex_log.c, ex_schema.c, ex_stat.c, ex_thread.c, and rotn_encrypt.c.
#define WT_PANIC

WiredTiger library panic.

This error indicates an underlying problem that requires a database restart. The application may exit immediately, no further WiredTiger calls are required (and further calls will themselves immediately fail).

#define WT_ROLLBACK

Conflict between concurrent operations.

This error is generated when an operation cannot be completed due to a conflict with concurrent operations. The operation may be retried; if a transaction is in progress, it should be rolled back and the operation retried in a new transaction.

#define WT_RUN_RECOVERY

Recovery must be run to continue.

This error is generated when wiredtiger_open is configured to return an error if recovery is required to use the database.

Typedef Documentation

typedef struct __wt_pack_stream WT_PACK_STREAM

Streaming interface to packing.

This allows applications to pack or unpack records one field at a time. This is an opaque handle returned by wiredtiger_pack_start or wiredtiger_unpack_start. It must be closed with wiredtiger_pack_close.

Enumeration Type Documentation

Asynchronous operation types.

Enumerator
WT_AOP_NONE 

No operation type set.

WT_AOP_COMPACT 

WT_ASYNC_OP::compact.

WT_AOP_INSERT 

WT_ASYNC_OP::insert.

WT_AOP_REMOVE 

WT_ASYNC_OP::remove.

WT_AOP_SEARCH 

WT_ASYNC_OP::search.

WT_AOP_UPDATE 

WT_ASYNC_OP::update.

Function Documentation

int wiredtiger_config_parser_open ( WT_SESSION session,
const char *  config,
size_t  len,
WT_CONFIG_PARSER **  config_parserp 
)

Create a handle that can be used to parse or create configuration strings compatible with WiredTiger APIs.

This API is outside the scope of a WiredTiger connection handle, since applications may need to generate configuration strings prior to calling wiredtiger_open.

Parameters
sessionthe session handle to be used for error reporting (if NULL, error messages will be written to stderr).
configthe configuration string being parsed. The string must remain valid for the lifetime of the parser handle.
lenthe number of valid bytes in config
[out]config_parserpA pointer to the newly opened handle
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
const char *config_string =
"path=/dev/loop,page_size=1024,log=(archive=true,file_max=20MB)";
NULL, config_string, strlen(config_string), &parser));
error_check(parser->close(parser));
int wiredtiger_open ( const char *  home,
WT_EVENT_HANDLER errhandler,
const char *  config,
WT_CONNECTION **  connectionp 
)

Open a connection to a database.

error_check(wiredtiger_open(home, NULL,
"create,cache_size=5GB,log=(enabled,recover=on),statistics=(all)",
&conn));
Parameters
homeThe path to the database home directory. See Database Home Directory for more information.
errhandlerAn error handler. If NULL, a builtin error handler is installed that writes error messages to stderr. See Error handling using the WT_EVENT_HANDLER for more information.
configConfiguration string, see Configuration Strings. Permitted values:
NameEffectValues
async = (asynchronous operations configuration options.a set of related configuration options defined below.
    enabledenable asynchronous operation.a boolean flag; default false.
    ops_maxmaximum number of expected simultaneous asynchronous operations.an integer between 1 and 4096; default 1024.
    threadsthe number of worker threads to service asynchronous requests. Each worker thread uses a session from the configured session_max.an integer between 1 and 20; default 2.
)
buffer_alignmentin-memory alignment (in bytes) for buffers used for I/O. The default value of -1 indicates a platform-specific alignment value should be used (4KB on Linux systems when direct I/O is configured, zero elsewhere).an integer between -1 and 1MB; default -1.
builtin_extension_configA structure where the keys are the names of builtin extensions and the values are passed to WT_CONNECTION::load_extension as the config parameter (for example, builtin_extension_config={zlib={compression_level=3}}).a string; default empty.
cache_overheadassume the heap allocator overhead is the specified percentage, and adjust the cache usage by that amount (for example, if there is 10GB of data in cache, a percentage of 10 means WiredTiger treats this as 11GB). This value is configurable because different heap allocators have different overhead and different workloads will have different heap allocation sizes and patterns, therefore applications may need to adjust this value based on allocator choice and behavior in measured workloads.an integer between 0 and 30; default 8.
cache_sizemaximum heap memory to allocate for the cache. A database should configure either cache_size or shared_cache but not both.an integer between 1MB and 10TB; default 100MB.
checkpoint = (periodically checkpoint the database. Enabling the checkpoint server uses a session from the configured session_max.a set of related configuration options defined below.
    log_sizewait for this amount of log record bytes to be written to the log between each checkpoint. If non-zero, this value will use a minimum of the log file size. 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.
    waitseconds to wait between each checkpoint; setting this value above 0 configures periodic checkpoints.an integer between 0 and 100000; default 0.
)
checkpoint_syncflush files to stable storage when closing or writing checkpoints.a boolean flag; default true.
compatibility = (set compatibility version of database. Changing the compatibility version requires that there are no active operations for the duration of the call.a set of related configuration options defined below.
    releasecompatibility release version string.a string; default empty.
)
config_basewrite the base configuration file if creating the database. If false in the config passed directly to wiredtiger_open, will ignore any existing base configuration file in addition to not creating one. See WiredTiger.basecfg file for more information.a boolean flag; default true.
createcreate the database if it does not exist.a boolean flag; default false.
direct_ioUse O_DIRECT on POSIX systems, and FILE_FLAG_NO_BUFFERING on Windows to access files. Options are given as a list, such as "direct_io=[data]". Configuring direct_io requires care, see Direct I/O for important warnings. Including "data" will cause WiredTiger data files to use direct I/O, including "log" will cause WiredTiger log files to use direct I/O, and including "checkpoint" will cause WiredTiger data files opened at a checkpoint (i.e: read only) to use direct I/O. direct_io should be combined with write_through to get the equivalent of O_DIRECT on Windows.a list, with values chosen from the following options: "checkpoint", "data", "log"; default empty.
encryption = (configure an encryptor for system wide metadata and logs. If a system wide encryptor is set, it is also used for encrypting data files and tables, unless encryption configuration is explicitly set for them when they are created with WT_SESSION::create.a set of related configuration options defined below.
    keyidAn identifier that identifies a unique instance of the encryptor. It is stored in clear text, and thus is available when the wiredtiger database is reopened. On the first use of a (name, keyid) combination, the WT_ENCRYPTOR::customize function is called with the keyid as an argument.a string; default empty.
    namePermitted values are "none" or custom encryption engine name created with WT_CONNECTION::add_encryptor. See Encryptors for more information.a string; default none.
    secretkeyA string that is passed to the WT_ENCRYPTOR::customize function. It is never stored in clear text, so must be given to any subsequent wiredtiger_open calls to reopen the database. It must also be provided to any "wt" commands used with this database.a string; default empty.
)
error_prefixprefix string for error messages.a string; default empty.
eviction = (eviction configuration options.a set of related configuration options defined below.
    threads_maxmaximum 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. Each eviction worker thread uses a session from the configured session_max.an integer between 1 and 20; default 8.
    threads_minminimum 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_checkpoint_targetperform eviction at the beginning of checkpoints to bring the dirty content in cache to this level, expressed as a percentage of the total cache size. Ignored if set to zero or in_memory is true.an integer between 0 and 99; default 5.
eviction_dirty_targetperform eviction in worker threads when the cache contains at least this much dirty content, expressed as a percentage of the total cache size.an integer between 1 and 99; default 5.
eviction_dirty_triggertrigger application threads to perform eviction when the cache contains at least this much dirty content, expressed as a percentage of the total cache size. This setting only alters behavior if it is lower than eviction_trigger.an integer between 1 and 99; default 20.
eviction_targetperform eviction in worker threads when the cache contains at least this much content, expressed as a percentage of the total cache size. Must be less than eviction_trigger.an integer between 10 and 99; default 80.
eviction_triggertrigger application threads to perform eviction when the cache contains at least this much content, expressed as a percentage of the total cache size.an integer between 10 and 99; default 95.
exclusivefail if the database already exists, generally used with the create option.a boolean flag; default false.
extensionslist of shared library extensions to load (using dlopen). Any values specified to a library extension are passed to WT_CONNECTION::load_extension as the config parameter (for example, extensions=(/path/ext.so={entry=my_entry})).a list of strings; default empty.
file_extendfile extension configuration. If set, extend files of the set type in allocations of the set size, instead of a block at a time as each new block is written. For example, file_extend=(data=16MB).a list, with values chosen from the following options: "data", "log"; default empty.
file_manager = (control how file handles are managed.a set of related configuration options defined below.
    close_handle_minimumnumber of handles open before the file manager will look for handles to close.an integer greater than or equal to 0; default 250.
    close_idle_timeamount of time in seconds a file handle needs to be idle before attempting to close it. A setting of 0 means that idle handles are not closed.an integer between 0 and 100000; default 30.
    close_scan_intervalinterval in seconds at which to check for files that are inactive and close them.an integer between 1 and 100000; default 10.
)
in_memorykeep data in-memory only. See In-memory databases for more information.a boolean flag; default false.
log = (enable logging. Enabling logging uses three sessions from the configured session_max.a set of related configuration options defined below.
    archiveautomatically archive unneeded log files.a boolean flag; default true.
    compressorconfigure a compressor for log records. Permitted values are "none" or custom compression engine name created with WT_CONNECTION::add_compressor. If WiredTiger has builtin support for "lz4", "snappy", "zlib" or "zstd" compression, these names are also available. See Compressors for more information.a string; default none.
    enabledenable logging subsystem.a boolean flag; default false.
    file_maxthe maximum size of log files.an integer between 100KB and 2GB; default 100MB.
    paththe name of a directory into which log files are written. The directory must already exist. If the value is not an absolute path, the path is relative to the database home (see Absolute paths for more information).a string; default ".".
    preallocpre-allocate log files.a boolean flag; default true.
    recoverrun recovery or error if recovery needs to run after an unclean shutdown.a string, chosen from the following options: "error", "on"; default on.
    zero_fillmanually write zeroes into log files.a boolean flag; default false.
)
lsm_manager = (configure database wide options for LSM tree management. The LSM manager is started automatically the first time an LSM tree is opened. The LSM manager uses a session from the configured session_max.a set of related configuration options defined below.
    mergemerge LSM chunks where possible.a boolean flag; default true.
    worker_thread_maxConfigure a set of threads to manage merging LSM trees in the database. Each worker thread uses a session handle from the configured session_max.an integer between 3 and 20; default 4.
)
mmapUse memory mapping to access files when possible.a boolean flag; default true.
multiprocesspermit sharing between processes (will automatically start an RPC server for primary processes and use RPC for secondary processes). Not yet supported in WiredTiger.a boolean flag; default false.
readonlyopen connection in read-only mode. The database must exist. All methods that may modify a database are disabled. See Database read-only mode for more information.a boolean flag; default false.
session_maxmaximum expected number of sessions (including server threads).an integer greater than or equal to 1; default 100.
shared_cache = (shared cache configuration options. A database should configure either a cache_size or a shared_cache not both. Enabling a shared cache uses a session from the configured session_max.a set of related configuration options defined below.
    chunkthe granularity that a shared cache is redistributed.an integer between 1MB and 10TB; default 10MB.
    namethe name of a cache that is shared between databases or "none" when no shared cache is configured.a string; default none.
    quotamaximum size of cache this database can be allocated from the shared cache. Defaults to the entire shared cache size.an integer; default 0.
    reserveamount 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.
    sizemaximum 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.
)
statisticsMaintain 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", "cache_walk", "fast", "none", "clear", "tree_walk"; default none.
statistics_log = (log any statistics the database is configured to maintain, to a file. See Statistics for more information. Enabling the statistics log server uses a session from the configured session_max.a set of related configuration options defined below.
    jsonencode statistics in JSON format.a boolean flag; default false.
    on_closelog statistics on database close.a boolean flag; default false.
    paththe name of a directory into which statistics files are written. The directory must already exist. If the value is not an absolute path, the path is relative to the database home (see Absolute paths for more information).a string; default ".".
    sourcesif 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.
    timestampa timestamp prepended to each log record, may contain strftime conversion specifications, when json is configured, defaults to "%FT%Y.000Z".a string; default "%b %d %H:%M:%S".
    waitseconds to wait between each write of the log records; setting this value above 0 configures statistics logging.an integer between 0 and 100000; default 0.
)
transaction_sync = (how to sync log records when the transaction commits.a set of related configuration options defined below.
    enabledwhether to sync the log on every commit by default, can be overridden by the sync setting to WT_SESSION::commit_transaction.a boolean flag; default false.
    methodthe method used to ensure log records are stable on disk, see Commit-level durability for more information.a string, chosen from the following options: "dsync", "fsync", "none"; default fsync.
)
use_environmentuse the WIREDTIGER_CONFIG and WIREDTIGER_HOME environment variables if the process is not running with special privileges. See Database Home Directory for more information.a boolean flag; default true.
use_environment_privuse the WIREDTIGER_CONFIG and WIREDTIGER_HOME environment variables even if the process is running with special privileges. See Database Home Directory for more information.a boolean flag; default false.
verboseenable 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", "evict_stuck", "evictserver", "fileops", "handleops", "log", "lookaside_activity", "lsm", "lsm_manager", "metadata", "mutex", "overflow", "read", "rebalance", "reconcile", "recovery", "recovery_progress", "salvage", "shared_cache", "split", "temporary", "thread_group", "timestamp", "transaction", "verify", "version", "write"; default empty.
write_throughUse FILE_FLAG_WRITE_THROUGH on Windows to write to files. Ignored on non-Windows systems. Options are given as a list, such as "write_through=[data]". Configuring write_through requires care, see Direct I/O for important warnings. Including "data" will cause WiredTiger data files to write through cache, including "log" will cause WiredTiger log files to write through cache. write_through should be combined with direct_io to get the equivalent of POSIX O_DIRECT on Windows.a list, with values chosen from the following options: "data", "log"; default empty.
Additionally, if files named WiredTiger.config or WiredTiger.basecfg appear in the WiredTiger home directory, they are read for configuration values (see WiredTiger.config file and WiredTiger.basecfg file for details). See Configuration ordering for ordering of the configuration mechanisms.
[out]connectionpA pointer to the newly opened connection handle
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
Examples:
ex_access.c, ex_async.c, ex_call_center.c, ex_cursor.c, ex_encrypt.c, ex_extending.c, ex_extractor.c, ex_file_system.c, ex_hello.c, ex_log.c, ex_pack.c, ex_schema.c, ex_stat.c, and ex_thread.c.
int wiredtiger_pack_close ( WT_PACK_STREAM ps,
size_t *  usedp 
)

Close a packing stream.

Parameters
psthe packing stream handle
[out]usedpthe number of bytes in the buffer used by the stream
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
int wiredtiger_pack_int ( WT_PACK_STREAM ps,
int64_t  i 
)

Pack a signed integer into a packing stream.

Parameters
psthe packing stream handle
ia signed integer to pack
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
int wiredtiger_pack_item ( WT_PACK_STREAM ps,
WT_ITEM item 
)

Pack an item into a packing stream.

Parameters
psthe packing stream handle
iteman item to pack
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
int wiredtiger_pack_start ( WT_SESSION session,
const char *  format,
void *  buffer,
size_t  size,
WT_PACK_STREAM **  psp 
)

Start a packing operation into a buffer with the given format string.

This should be followed by a series of calls to wiredtiger_pack_item, wiredtiger_pack_int, wiredtiger_pack_str or wiredtiger_pack_uint to fill in the values.

Parameters
sessionthe session handle
formatthe data format, see Packing and Unpacking Data
buffera pointer to memory to hold the packed data
sizethe size of the buffer
[out]pspthe new packing stream handle
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
int wiredtiger_pack_str ( WT_PACK_STREAM ps,
const char *  s 
)

Pack a string into a packing stream.

Parameters
psthe packing stream handle
sa string to pack
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
int wiredtiger_pack_uint ( WT_PACK_STREAM ps,
uint64_t  u 
)

Pack an unsigned integer into a packing stream.

Parameters
psthe packing stream handle
uan unsigned integer to pack
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
const char* wiredtiger_strerror ( int  error)

Return information about a WiredTiger error as a string (see WT_SESSION::strerror for a thread-safe API).

const char *key = "non-existent key";
cursor->set_key(cursor, key);
if ((ret = cursor->remove(cursor)) != 0) {
fprintf(stderr,
"cursor.remove: %s\n", wiredtiger_strerror(ret));
return (ret);
}
Parameters
errora return value from a WiredTiger, ISO C, or POSIX standard API
Returns
a string representation of the error
Examples:
ex_async.c, and ex_file_system.c.
int wiredtiger_struct_pack ( WT_SESSION session,
void *  buffer,
size_t  size,
const char *  format,
  ... 
)

Pack a structure into a buffer.

See Packing and Unpacking Data for a description of the permitted format strings.

Packing Examples

For example, the string "iSh" will pack a 32-bit integer followed by a NUL-terminated string, followed by a 16-bit integer. The default, big-endian encoding will be used, with no alignment. This could be used in C as follows:

char buf[100];
session, buf, sizeof(buf), "iSh", 42, "hello", -3));

Then later, the values can be unpacked as follows:

int i;
char *s;
short h;
session, buf, sizeof(buf), "iSh", &i, &s, &h));
Parameters
sessionthe session handle
buffera pointer to a packed byte array
sizethe number of valid bytes in the buffer
formatthe data format, see Packing and Unpacking Data
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
Examples:
ex_pack.c.
int wiredtiger_struct_size ( WT_SESSION session,
size_t *  sizep,
const char *  format,
  ... 
)

Calculate the size required to pack a structure.

Note that for variable-sized fields including variable-sized strings and integers, the calculated sized merely reflects the expected sizes specified in the format string itself.

size_t size;
session, &size, "iSh", 42, "hello", -3));
Parameters
sessionthe session handle
sizepa location where the number of bytes needed for the matching call to wiredtiger_struct_pack is returned
formatthe data format, see Packing and Unpacking Data
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
Examples:
ex_pack.c.
int wiredtiger_struct_unpack ( WT_SESSION session,
const void *  buffer,
size_t  size,
const char *  format,
  ... 
)

Unpack a structure from a buffer.

Reverse of wiredtiger_struct_pack: gets values out of a packed byte string.

int i;
char *s;
short h;
session, buf, sizeof(buf), "iSh", &i, &s, &h));
Parameters
sessionthe session handle
buffera pointer to a packed byte array
sizethe number of valid bytes in the buffer
formatthe data format, see Packing and Unpacking Data
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
Examples:
ex_extractor.c, ex_pack.c, and ex_schema.c.
int wiredtiger_unpack_int ( WT_PACK_STREAM ps,
int64_t *  ip 
)

Unpack a signed integer from a packing stream.

Parameters
psthe packing stream handle
[out]ipthe unpacked signed integer
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
int wiredtiger_unpack_item ( WT_PACK_STREAM ps,
WT_ITEM item 
)

Unpack an item from a packing stream.

Parameters
psthe packing stream handle
iteman item to unpack
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
int wiredtiger_unpack_start ( WT_SESSION session,
const char *  format,
const void *  buffer,
size_t  size,
WT_PACK_STREAM **  psp 
)

Start an unpacking operation from a buffer with the given format string.

This should be followed by a series of calls to wiredtiger_unpack_item, wiredtiger_unpack_int, wiredtiger_unpack_str or wiredtiger_unpack_uint to retrieve the packed values.

Parameters
sessionthe session handle
formatthe data format, see Packing and Unpacking Data
buffera pointer to memory holding the packed data
sizethe size of the buffer
[out]pspthe new packing stream handle
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
int wiredtiger_unpack_str ( WT_PACK_STREAM ps,
const char **  sp 
)

Unpack a string from a packing stream.

Parameters
psthe packing stream handle
[out]spthe unpacked string
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
int wiredtiger_unpack_uint ( WT_PACK_STREAM ps,
uint64_t *  up 
)

Unpack an unsigned integer from a packing stream.

Parameters
psthe packing stream handle
[out]upthe unpacked unsigned integer
Returns
zero on success and a non-zero error code on failure. See Error handling for details.
const char* wiredtiger_version ( int *  majorp,
int *  minorp,
int *  patchp 
)

Get version information.

printf("WiredTiger version %s\n", wiredtiger_version(NULL, NULL, NULL));
int major_v, minor_v, patch;
(void)wiredtiger_version(&major_v, &minor_v, &patch);
printf("WiredTiger version is %d, %d (patch %d)\n",
major_v, minor_v, patch);
Parameters
majorpa location where the major version number is returned
minorpa location where the minor version number is returned
patchpa location where the patch version number is returned
Returns
a string representation of the version