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Berkeley DB: DbSequence::stat
DbSequence::stat
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#include <db_cxx.h>
int
Db::stat(void *sp, u_int32_t flags);
int
Db::stat_print(u_int32_t flags);
Description: DbSequence::stat
The DbSequence::stat method creates a statistical structure and copies a
pointer to it into user-specified memory locations. Specifically, if
sp 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 DbEnv::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sequence, the information returned by DbSequence::stat may be out-of-date.
The DbSequence::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 statistics are stored in a structure of type DB_SEQUENCE_STAT. The
following fields will be filled in:
- u_int32_t st_wait;
- The number of times a thread of control was forced to wait on the
handle mutex.
- u_int32_t st_nowait;
- The number of times that a thread of control was able to obtain handle
mutex without waiting.
- db_seq_t st_current;
- The current value of the sequence in the database.
- db_seq_t st_value;
- The current cached value of 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.
- int32_t st_cache_size;
- The number of values that will be cached in this handle.
- u_int32_t st_flags;
- The flags value for the sequence.
Parameters
- flags
- The flags parameter must be set by bitwise inclusively OR'ing together one or more
of the following values:
- DB_STAT_CLEAR
- Reset statistics after printing their values.
The DbSequence::stat_print method
either returns a non-zero error value
or throws an exception that encapsulates a non-zero error value on
failure, and returns 0 on success.
Description: DbSequence::stat_print
The DbSequence::stat_print method prints diagnostic information to the output
channel described by the DbEnv::set_msgfile method.
Parameters
- flags
- The flags parameter must be set by bitwise inclusively OR'ing together one or more
of the following values:
- DB_STAT_CLEAR
- Reset statistics after printing their values.
Class
DbSequence
See Also
Sequences and Related Methods
Copyright (c) 1996-2004 Sleepycat Software, Inc. - All rights reserved.
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