DB_SEQUENCE->stat()

#include <db.h>

int
DB_SEQUENCE->stat(DB_SEQUENCE *db, DB_SEQUENCE_STAT **spp, 
                  u_int32_t flags); 

The DB_SEQUENCE->stat() method creates a statistical structure and copies a pointer to it into user-specified memory locations. Specifically, if spp is non-NULL, a pointer to the statistics for the database are copied into the memory location to which it refers.

Statistical structures are stored in allocated memory. If application-specific allocation routines have been declared (see DB_ENV->set_alloc() for more information), they are used to allocate the memory; otherwise, the standard C library malloc(3) is used. The caller is responsible for deallocating the memory. To deallocate the memory, free the memory reference; references inside the returned memory need not be individually freed.

In the presence of multiple threads or processes accessing an active sequence, the information returned by DB_SEQUENCE->stat() may be out-of-date.

The DB_SEQUENCE->stat() method cannot be transaction-protected. For this reason, it should be called in a thread of control that has no open cursors or active transactions.

The DB_SEQUENCE->stat() method returns a non-zero error value on failure and 0 on success.

The statistics are stored in a structure of type DB_SEQUENCE_STAT. The following fields will be filled in:

• int32_t st_cache_size;

  The number of values that will be cached in this handle.

• db_seq_t st_current;

  The current value of the sequence in the database.

• u_int32_t st_flags;

  The flags value for the sequence.

• db_seq_t st_last_value;

  The last cached value of the sequence.

• db_seq_t st_min;

  The minimum permitted value of the sequence.

• db_seq_t st_max;

  The maximum permitted value of the sequence.

• uintmax_t st_nowait;

  The number of times that a thread of control was able to obtain handle mutex without waiting.

• db_seq_t st_value;

  The current cached value of the sequence.

• uintmax_t st_wait;

  The number of times a thread of control was forced to wait on the handle mutex.

Parameters

flags

The flags parameter must be set by bitwise inclusively OR'ing together one or more of the following values:

• DB_STAT_ALL

  Display all available information.

• DB_STAT_CLEAR

  Reset statistics after printing their values.

Class

DB_SEQUENCE

See Also

Sequences and Related Methods