The Statistics Group contains the API for capacity and performance indicators. More...

Classes
struct	mdbm_stats

struct	mdbm_db_info

struct	mdbm_chunk_info

struct	mdbm_bucket_stat

struct	mdbm_stat_info

struct	mdbm_window_stats

Macros
#define	MDBM_CLOCK_STANDARD 0

#define	MDBM_CLOCK_TSC 1

#define	MDBM_STATS_BASIC 0x1
	Basic stats only. More...

#define	MDBM_STATS_TIMED 0x2
	SLOW! Stats that call get-time functions. More...

#define	MDBM_STAT_CB_INC 0x0
	Basic stat. More...

#define	MDBM_STAT_CB_SET 0x1
	Basic stat. More...

#define	MDBM_STAT_CB_ELAPSED 0x2
	Value is a time delta. More...

#define	MDBM_STAT_CB_TIME 0x3
	Value is the stat time. More...

#define	COMBINE_STAT_TAG(tag, flag) (tag \| (flag<<16))

#define	MDBM_STAT_TAG_FETCH 1 /* Successful fetch stats-callback counter */
	The various stats metrics (tags): All time/latency related stats (defined below) require: mdbm_set_stats_func(db, flags\|MDBM_STAT_CB_TIME, ...) More...

#define	MDBM_STAT_TAG_STORE 2 /* Successful store stats-callback counter */

#define	MDBM_STAT_TAG_DELETE 3 /* Successful delete stats-callback counter */

#define	MDBM_STAT_TAG_LOCK 4 /* lock stats-callback counter (not implemented) */

#define	MDBM_STAT_TAG_FETCH_UNCACHED 5 /* Cache-miss with cache+backingstore */

#define	MDBM_STAT_TAG_GETPAGE 6 /* Generic access counter in windowed mode */

#define	MDBM_STAT_TAG_GETPAGE_UNCACHED 7 /* Windowed-mode "miss" (load new page into window) */

#define	MDBM_STAT_TAG_CACHE_EVICT 8 /* Cache evict stats-callback counter */

#define	MDBM_STAT_TAG_CACHE_STORE 9 /* Successful cache store counter (BS only) */

#define	MDBM_STAT_TAG_PAGE_STORE 10 /* Successful page-level store indicator */

#define	MDBM_STAT_TAG_PAGE_DELETE 11 /* Successful page-level delete indicator */

#define	MDBM_STAT_TAG_SYNC 12 /* Counter of mdbm_syncs and fsyncs */

#define	MDBM_STAT_TAG_FETCH_NOT_FOUND 13 /* Fetch cannot find a key in MDBM */

#define	MDBM_STAT_TAG_FETCH_ERROR 14 /* Error occurred during fetch */

#define	MDBM_STAT_TAG_STORE_ERROR 15 /* Error occurred during store (e.g. MODIFY failed) */

#define	MDBM_STAT_TAG_DELETE_FAILED 16 /* Delete failed: cannot find a key in MDBM */

#define	MDBM_STAT_TAG_FETCH_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_FETCH, MDBM_STAT_CB_ELAPSED)
	Fetch latency (expensive to collect) More...

#define	MDBM_STAT_TAG_STORE_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_STORE, MDBM_STAT_CB_ELAPSED)
	Store latency (expensive to collect) More...

#define	MDBM_STAT_TAG_DELETE_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_DELETE, MDBM_STAT_CB_ELAPSED)
	Delete latency (expensive to collect) More...

#define	MDBM_STAT_TAG_FETCH_TIME COMBINE_STAT_TAG(MDBM_STAT_TAG_FETCH, MDBM_STAT_CB_TIME)
	timestamp of last fetch (not yet implemented) More...

#define	MDBM_STAT_TAG_STORE_TIME COMBINE_STAT_TAG(MDBM_STAT_TAG_STORE, MDBM_STAT_CB_TIME)
	timestamp of last store (not yet implemented) More...

#define	MDBM_STAT_TAG_DELETE_TIME COMBINE_STAT_TAG(MDBM_STAT_TAG_DELETE, MDBM_STAT_CB_TIME)
	timestamp of last delete (not yet implemented) More...

#define	MDBM_STAT_TAG_FETCH_UNCACHED_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_FETCH_UNCACHED, MDBM_STAT_CB_ELAPSED)
	Cache miss latency for cache+Backingstore only (expensive to collect) More...

#define	MDBM_STAT_TAG_GETPAGE_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_GETPAGE, MDBM_STAT_CB_ELAPSED)
	access latency in windowed mode (expensive to collect) More...

#define	MDBM_STAT_TAG_GETPAGE_UNCACHED_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_GETPAGE_UNCACHED, MDBM_STAT_CB_ELAPSED)
	windowed-mode miss latency (expensive to collect) More...

#define	MDBM_STAT_TAG_CACHE_EVICT_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_CACHE_EVICT, MDBM_STAT_CB_ELAPSED)
	cache evict latency (expensive to collect) More...

#define	MDBM_STAT_TAG_CACHE_STORE_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_CACHE_STORE, MDBM_STAT_CB_ELAPSED)
	Cache store latency in Cache+backingstore mode only (expensive to collect) More...

#define	MDBM_STAT_TAG_PAGE_STORE_VALUE COMBINE_STAT_TAG(MDBM_STAT_TAG_PAGE_STORE, MDBM_STAT_CB_SET)
	Indicates a store occurred on a particular page. More...

#define	MDBM_STAT_TAG_PAGE_DELETE_VALUE COMBINE_STAT_TAG(MDBM_STAT_TAG_PAGE_DELETE, MDBM_STAT_CB_SET)
	Indicates a delete occurred on a particular page. More...

#define	MDBM_STAT_TAG_SYNC_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_SYNC, MDBM_STAT_CB_ELAPSED)
	mdbm_sync/fsync latency (expensive to collect) More...

#define	MDBM_STAT_DELETED 0x1
	Deprecated. More...

#define	MDBM_STAT_KEYS 0x2
	Deprecated. More...

#define	MDBM_STAT_VALUES 0x4
	Deprecated. More...

#define	MDBM_STAT_PAGES_ONLY 0x8
	Deprecated. More...

#define	MDBM_STAT_NOLOCK 0x80
	Do not lock for stat operation. More...

#define	MDBM_STAT_BUCKETS 20
	Number of buckets for stat histograms. More...

Typedefs
typedef struct mdbm_stats	mdbm_stats_t

typedef uint64_t	mdbm_counter_t

typedef void(*	mdbm_stat_cb )(MDBM db, int tag, int flags, uint64_t value, void user)
	The general stats callback function definition. More...

typedef struct mdbm_db_info	mdbm_db_info_t

typedef struct mdbm_chunk_info	mdbm_chunk_info_t

typedef int(*	mdbm_chunk_iterate_func_t )(void user, const mdbm_chunk_info_t info)

typedef struct mdbm_bucket_stat	mdbm_bucket_stat_t

typedef struct mdbm_stat_info	mdbm_stat_info_t

typedef struct mdbm_window_stats	mdbm_window_stats_t

Enumerations
enum	mdbm_stat_type { MDBM_STAT_TYPE_FETCH = 0, MDBM_STAT_TYPE_STORE = 1, MDBM_STAT_TYPE_DELETE = 2, MDBM_STAT_TYPE_MAX = MDBM_STAT_TYPE_DELETE }

enum	{ MDBM_PTYPE_FREE = 0, MDBM_PTYPE_DATA = 1, MDBM_PTYPE_DIR = 2, MDBM_PTYPE_LOB = 3 }

Functions
int	mdbm_get_stat_counter (MDBM db, mdbm_stat_type type, mdbm_counter_t value)
	Gets the number of operations performed for a stat type. More...

int	mdbm_get_stat_time (MDBM db, mdbm_stat_type type, time_t value)
	Gets the last time when an type operation was performed. More...

void	mdbm_reset_stat_operations (MDBM *db)
	Resets the stat counter and last-time performed for fetch, store, and remove operations. More...

int	mdbm_enable_stat_operations (MDBM *db, int flags)
	Enables and disables gathering of stat counters and/or last-time performed for fetch, store, and remove operations. More...

int	mdbm_set_stat_time_func (MDBM *db, int flags)
	Tells the MDBM library whether to use TSC (CPU TimeStamp Counters) for timing the performance of fetch, store and delete operations. More...

const char *	mdbm_get_stat_name (int tag)
	Gets the name of a stat. More...

int	mdbm_set_stats_func (MDBM db, int flags, mdbm_stat_cb cb, void user)
	Sets the callback function for a stat. More...

void	mdbm_stat_all_page (MDBM *db)
	Prints to stdout various pieces of information, specifically: Total mapped db size, Total number of entries, ADDRESS SPACE page efficiency, ADDRESS SPACE byte efficiency, PHYSICAL MEM/DISK SPACE efficiency, Average bytes per record, Maximum B-tree level, Minimum B-tree level, Minimum free bytes on page, Minimum free bytes on page post compress. More...

int	mdbm_get_stats (MDBM db, mdbm_stats_t s, size_t stats_size)
	Gets a a stats block with individual stat values. More...

int	mdbm_get_db_info (MDBM db, mdbm_db_info_t info)
	Gets configuration information about a database. More...

int	mdbm_chunk_iterate (MDBM db, mdbm_chunk_iterate_func_t func, int flags, void user)
	Iterates over all pages (starting at page 0). More...

int	mdbm_get_db_stats (MDBM db, mdbm_db_info_t info, mdbm_stat_info_t *stats, int flags)
	Gets overall database stats. More...

int	mdbm_get_window_stats (MDBM db, mdbm_window_stats_t stats, size_t s_size)
	Used to retrieve statistics about windowing usage on the associated database. More...

uint64_t	mdbm_count_records (MDBM *db)
	Counts the number of records in an MDBM. More...

mdbm_ubig_t	mdbm_count_pages (MDBM *db)
	Counts the number of pages used by an MDBM. More...

Detailed Description

The Statistics Group contains the API for capacity and performance indicators.

Macro Definition Documentation

#define MDBM_CLOCK_STANDARD 0

#define MDBM_CLOCK_TSC 1

#define MDBM_STATS_BASIC 0x1

Basic stats only.

#define MDBM_STATS_TIMED 0x2

SLOW! Stats that call get-time functions.

#define MDBM_STAT_CB_INC 0x0

Basic stat.

Value is a delta.

#define MDBM_STAT_CB_SET 0x1

Basic stat.

Value is the current value.

#define MDBM_STAT_CB_ELAPSED 0x2

Value is a time delta.

#define MDBM_STAT_CB_TIME 0x3

Value is the stat time.

#define COMBINE_STAT_TAG	(	tag,
		flag
	)	(tag \| (flag<<16))

#define MDBM_STAT_TAG_FETCH 1 /* Successful fetch stats-callback counter */

The various stats metrics (tags): All time/latency related stats (defined below) require: mdbm_set_stats_func(db, flags|MDBM_STAT_CB_TIME, ...)

#define MDBM_STAT_TAG_STORE 2 /* Successful store stats-callback counter */

#define MDBM_STAT_TAG_DELETE 3 /* Successful delete stats-callback counter */

#define MDBM_STAT_TAG_LOCK 4 /* lock stats-callback counter (not implemented) */

#define MDBM_STAT_TAG_FETCH_UNCACHED 5 /* Cache-miss with cache+backingstore */

#define MDBM_STAT_TAG_GETPAGE 6 /* Generic access counter in windowed mode */

#define MDBM_STAT_TAG_GETPAGE_UNCACHED 7 /* Windowed-mode "miss" (load new page into window) */

#define MDBM_STAT_TAG_CACHE_EVICT 8 /* Cache evict stats-callback counter */

#define MDBM_STAT_TAG_CACHE_STORE 9 /* Successful cache store counter (BS only) */

#define MDBM_STAT_TAG_PAGE_STORE 10 /* Successful page-level store indicator */

#define MDBM_STAT_TAG_PAGE_DELETE 11 /* Successful page-level delete indicator */

#define MDBM_STAT_TAG_SYNC 12 /* Counter of mdbm_syncs and fsyncs */

#define MDBM_STAT_TAG_FETCH_NOT_FOUND 13 /* Fetch cannot find a key in MDBM */

#define MDBM_STAT_TAG_FETCH_ERROR 14 /* Error occurred during fetch */

#define MDBM_STAT_TAG_STORE_ERROR 15 /* Error occurred during store (e.g. MODIFY failed) */

#define MDBM_STAT_TAG_DELETE_FAILED 16 /* Delete failed: cannot find a key in MDBM */

#define MDBM_STAT_TAG_FETCH_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_FETCH, MDBM_STAT_CB_ELAPSED)

Fetch latency (expensive to collect)

#define MDBM_STAT_TAG_STORE_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_STORE, MDBM_STAT_CB_ELAPSED)

Store latency (expensive to collect)

#define MDBM_STAT_TAG_DELETE_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_DELETE, MDBM_STAT_CB_ELAPSED)

Delete latency (expensive to collect)

#define MDBM_STAT_TAG_FETCH_TIME COMBINE_STAT_TAG(MDBM_STAT_TAG_FETCH, MDBM_STAT_CB_TIME)

timestamp of last fetch (not yet implemented)

#define MDBM_STAT_TAG_STORE_TIME COMBINE_STAT_TAG(MDBM_STAT_TAG_STORE, MDBM_STAT_CB_TIME)

timestamp of last store (not yet implemented)

#define MDBM_STAT_TAG_DELETE_TIME COMBINE_STAT_TAG(MDBM_STAT_TAG_DELETE, MDBM_STAT_CB_TIME)

timestamp of last delete (not yet implemented)

#define MDBM_STAT_TAG_FETCH_UNCACHED_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_FETCH_UNCACHED, MDBM_STAT_CB_ELAPSED)

Cache miss latency for cache+Backingstore only (expensive to collect)

#define MDBM_STAT_TAG_GETPAGE_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_GETPAGE, MDBM_STAT_CB_ELAPSED)

access latency in windowed mode (expensive to collect)

#define MDBM_STAT_TAG_GETPAGE_UNCACHED_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_GETPAGE_UNCACHED, MDBM_STAT_CB_ELAPSED)

windowed-mode miss latency (expensive to collect)

#define MDBM_STAT_TAG_CACHE_EVICT_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_CACHE_EVICT, MDBM_STAT_CB_ELAPSED)

cache evict latency (expensive to collect)

#define MDBM_STAT_TAG_CACHE_STORE_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_CACHE_STORE, MDBM_STAT_CB_ELAPSED)

Cache store latency in Cache+backingstore mode only (expensive to collect)

#define MDBM_STAT_TAG_PAGE_STORE_VALUE COMBINE_STAT_TAG(MDBM_STAT_TAG_PAGE_STORE, MDBM_STAT_CB_SET)

Indicates a store occurred on a particular page.

Value returned by callback is the page number. It is up to the callback function to maintain a per-page count

#define MDBM_STAT_TAG_PAGE_DELETE_VALUE COMBINE_STAT_TAG(MDBM_STAT_TAG_PAGE_DELETE, MDBM_STAT_CB_SET)

Indicates a delete occurred on a particular page.

Value returned by callback is the page number. It is up to the callback function to maintain a per-page count

#define MDBM_STAT_TAG_SYNC_LATENCY COMBINE_STAT_TAG(MDBM_STAT_TAG_SYNC, MDBM_STAT_CB_ELAPSED)

mdbm_sync/fsync latency (expensive to collect)

#define MDBM_STAT_DELETED 0x1

Deprecated.

#define MDBM_STAT_KEYS 0x2

Deprecated.

#define MDBM_STAT_VALUES 0x4

Deprecated.

#define MDBM_STAT_PAGES_ONLY 0x8

Deprecated.

#define MDBM_STAT_NOLOCK 0x80

Do not lock for stat operation.

#define MDBM_STAT_BUCKETS 20

Number of buckets for stat histograms.

Typedef Documentation

typedef struct mdbm_stats mdbm_stats_t

typedef uint64_t mdbm_counter_t

typedef void(* mdbm_stat_cb)(MDBM *db, int tag, int flags, uint64_t value, void *user)

The general stats callback function definition.

Parameters

[in,out]	db	Database handle
[in]	tag	Integer identifier of the stat. Use mdbm_get_stat_name to get the string id.
[in]	flags	A MDBM_STAT_CB_* value indicating the kind of value.
[in]	value	Update to the indicated value
[in]	user	User-defined callback for data passed into mdbm_set_stats_func

typedef struct mdbm_db_info mdbm_db_info_t

typedef struct mdbm_chunk_info mdbm_chunk_info_t

typedef int(* mdbm_chunk_iterate_func_t)(void *user, const mdbm_chunk_info_t *info)

typedef struct mdbm_bucket_stat mdbm_bucket_stat_t

typedef struct mdbm_stat_info mdbm_stat_info_t

typedef struct mdbm_window_stats mdbm_window_stats_t

Enumeration Type Documentation

enum mdbm_stat_type

Enumerator
MDBM_STAT_TYPE_FETCH	fetch* operations
MDBM_STAT_TYPE_STORE	store* operations
MDBM_STAT_TYPE_DELETE	delete* operations
MDBM_STAT_TYPE_MAX

anonymous enum

Enumerator
MDBM_PTYPE_FREE	Page type free.
MDBM_PTYPE_DATA	Page type data.
MDBM_PTYPE_DIR	Page type directory.
MDBM_PTYPE_LOB	Page type large object.

Function Documentation

int mdbm_get_stat_counter	(	MDBM *	db,
		mdbm_stat_type	type,
		mdbm_counter_t *	value
	)

Gets the number of operations performed for a stat type.

Parameters

[in,out]	db	Database handle
[in]	type	Stat type to return
[out]	value	Pointer to returned stat's value

Returns: Stat counter status

Return values

-1	Error
0	Success

Values for type:

MDBM_STAT_TYPE_FETCH - For fetch* operations
MDBM_STAT_TYPE_STORE - For store* operations
MDBM_STAT_TYPE_DELETE - For delete* operations

Stat operations must be enabled for operations to be tracked. Use mdbm_enable_stat_operations to enable this feature.

Once enabled, statistics are persisted in the MDBM and are not reset on mdbm_close.

Use program `mdbm_stat -H' to display stat operation metrics stored in the header.

int mdbm_get_stat_time	(	MDBM *	db,
		mdbm_stat_type	type,
		time_t *	value
	)

Gets the last time when an type operation was performed.

Parameters

[in,out]	db	Database handle
[in]	type	Stat type to return.
[out]	value	Pointer to returned stat's value.

Returns: Stat time status

Return values

-1	Error
0	Success

Values for type:

MDBM_STAT_TYPE_FETCH - For fetch* operations
MDBM_STAT_TYPE_STORE - For store* operations
MDBM_STAT_TYPE_DELETE - For delete* operations

Stat operations must be enabled for operations to be tracked. Use mdbm_enable_stat_operations to enable this feature.

Once enabled, statistics are persisted in the MDBM and are not reset on mdbm_close.

Use program `mdbm_stat -H' to display stat operation metrics stored in the header.

void mdbm_reset_stat_operations ( MDBM * db )

Resets the stat counter and last-time performed for fetch, store, and remove operations.

Parameters

[in,out] db Database handle

Stat operations must be enabled for operations to be tracked. Use mdbm_enable_stat_operations to enable this feature. If stat operations are not enabled, using this function will merely reset and already cleared storage.

Use program `mdbm_stat -H' to display stat operation metrics stored in the header.

int mdbm_enable_stat_operations	(	MDBM *	db,
		int	flags
	)

Enables and disables gathering of stat counters and/or last-time performed for fetch, store, and remove operations.

Parameters

[in,out]	db	Database handle
[in]	flags	Enables stat operations so that we can track one or both of: Operations counters fetch, store and remove. Last timestamp when a fetch, store or delete was performed.

flags = MDBM_STATS_BASIC enables gathering only the stats counters. flags = MDBM_STATS_TIMED enables gathering only the stats timestamps. flags = (MDBM_STATS_BASIC | MDBM_STATS_TIMED) enables both the stats counters and timestamps. flags = 0 disables gathering of stats counters and timestamps.

Return values

-1	Error
0	Success

Use program `mdbm_stat -H' to display stat operation metrics stored in the header.

int mdbm_set_stat_time_func	(	MDBM *	db,
		int	flags
	)

Tells the MDBM library whether to use TSC (CPU TimeStamp Counters) for timing the performance of fetch, store and delete operations.

The standard behavior of timed stat operations is to use clock_gettime(MONOTONIC)

Parameters

[in,out]	db	Database handle
[in]	flags	flags == MDBM_CLOCK_TSC Enables use of TSC flags == MDBM_CLOCK_STANDARD Disables use of TSC

Return values

-1	Error
0	Success

const char* mdbm_get_stat_name ( int tag )

Gets the name of a stat.

Parameters

[in] tag Stat identifier

Returns: Name of stat identifier. "unknown_tag" is return if tag is unknown.

int mdbm_set_stats_func	(	MDBM *	db,
		int	flags,
		mdbm_stat_cb	cb,
		void *	user
	)

Sets the callback function for a stat.

Parameters

[in,out]	db	Database handle
[in]	flags	Passed to callback function
[in]	cb	Callback function
[in]	user	Opaque user information

Returns: Set stats function status

Return values

-1	Error, and errno is set
0	Success, and callback is set

void mdbm_stat_all_page ( MDBM * db )

Prints to stdout various pieces of information, specifically: Total mapped db size, Total number of entries, ADDRESS SPACE page efficiency, ADDRESS SPACE byte efficiency, PHYSICAL MEM/DISK SPACE efficiency, Average bytes per record, Maximum B-tree level, Minimum B-tree level, Minimum free bytes on page, Minimum free bytes on page post compress.

If there are large objects, it loops through and reports record entries per page.

NOTE: There is only a V2 implementation. V3 not currently supported.

Parameters

[in,out] db Database handle

int mdbm_get_stats	(	MDBM *	db,
		mdbm_stats_t *	s,
		size_t	stats_size
	)

Gets a a stats block with individual stat values.

Parameters

[in,out]	db	Database handle
[out]	s	Stats block
[in]	stats_size	Stats block s size. Only as many stats will be returned as according to this size. The stats block is filled from top-to-bottom.

Returns: Get stats status

Return values

-1	Error, and errno is set
0	Success

int mdbm_get_db_info	(	MDBM *	db,
		mdbm_db_info_t *	info
	)

Gets configuration information about a database.

Parameters

[in,out]	db	Database handle
[out]	info	Database information

Returns: Database info status

Return values

-1	Error, and errno is set
0	Success

int mdbm_chunk_iterate	(	MDBM *	db,
		mdbm_chunk_iterate_func_t	func,
		int	flags,
		void *	user
	)

Iterates over all pages (starting at page 0).

This function only does per-page iteration, where mdbm_iterate is intended for per-record iteration starting at a page number.

Parameters

[in,out]	db	Database handle
[in]	func	Function to invoke for each chunk
[in]	flags	Iterations flags (below)
[in]	user	Opaque user pointer passed to func

Returns: Chunk iterate status

Return values

-1	Error, and errno is set
0	Success

Values for flags mask:

MDBM_ITERATE_NOLOCK - Do not lock during iteration

int mdbm_get_db_stats	(	MDBM *	db,
		mdbm_db_info_t *	info,
		mdbm_stat_info_t *	stats,
		int	flags
	)

Gets overall database stats.

Parameters

[in,out]	db	Database handle
[out]	info	Database page-based stats
[out]	stats	Database record-based stats
[in]	flags	Iteration control (below)

Returns: Database stats status

Return values

-1	Error, errno is set
0	Success

Values for flags mask:

MDBM_STAT_NOLOCK - Do not lock for overall operation
MDBM_ITERATE_NOLOCK - Do no lock for page-based iteration

int mdbm_get_window_stats	(	MDBM *	db,
		mdbm_window_stats_t *	stats,
		size_t	s_size
	)

Used to retrieve statistics about windowing usage on the associated database.

The V3 statistics structure is as follows. It may be extended in later versions, in which case the s_size parameter should be set to the sizeof the struct used for that version.

typedef struct mdbm_window_stats {
    uint64_t w_num_reused;
    uint64_t w_num_remapped;
    uint32_t w_window_size;
    uint32_t w_max_window_used;
} mdbm_window_stats_t;

NOTE: V3 API

Parameters

[in,out]	db	Database handle
[out]	stats	Pointer to struct that will receive the statistics
[in]	s_size	Size of stats. Should be sizeof(mdbm_window_stats_t) for V3.

Returns: Get window stats status

Return values

-1	Error
0	Success

uint64_t mdbm_count_records ( MDBM * db )

Counts the number of records in an MDBM.

Parameters

[in] db Database handle.

Returns: Number of records stored in an MDBM (use instead of count_all_page).

mdbm_ubig_t mdbm_count_pages ( MDBM * db )

Counts the number of pages used by an MDBM.

Parameters

[in] db Database handle.

Returns: Number of pages: Count of all directory+data+LargeObject pages used by an MDBM

Classes

Macros

Typedefs

Enumerations

Functions

Detailed Description

Macro Definition Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation