99 lines
4.7 KiB
HTML
99 lines
4.7 KiB
HTML
<!--$Id: seq_stat.html 63573 2008-05-23 21:43:21Z trent.nelson $-->
|
|
<!--Copyright (c) 1997,2008 Oracle. All rights reserved.-->
|
|
<!--See the file LICENSE for redistribution information.-->
|
|
<html>
|
|
<head>
|
|
<title>Berkeley DB: DB_SEQUENCE->stat</title>
|
|
<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit.">
|
|
<meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++">
|
|
</head>
|
|
<body bgcolor=white>
|
|
<table width="100%"><tr valign=top>
|
|
<td>
|
|
<b>DB_SEQUENCE->stat</b>
|
|
</td>
|
|
<td align=right>
|
|
<a href="../api_c/api_core.html"><img src="../images/api.gif" alt="API"></a>
|
|
<a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a></td>
|
|
</tr></table>
|
|
<hr size=1 noshade>
|
|
<tt>
|
|
<b><pre>
|
|
#include <db.h>
|
|
<p>
|
|
int
|
|
DB_SEQUENCE->stat(DB_SEQUENCE *db, void *sp, u_int32_t flags);
|
|
<p>
|
|
int
|
|
DB_SEQUENCE->stat_print(DB_SEQUENCE *db, u_int32_t flags);
|
|
</pre></b>
|
|
<hr size=1 noshade>
|
|
<b>Description: DB_SEQUENCE->stat</b>
|
|
<p>The DB_SEQUENCE->stat method creates a statistical structure and copies a
|
|
pointer to it into user-specified memory locations. Specifically, if
|
|
<b>sp</b> is non-NULL, a pointer to the statistics for the database are
|
|
copied into the memory location to which it refers.</p>
|
|
<p>Statistical structures are stored in allocated memory. If application-specific allocation
|
|
routines have been declared (see <a href="../api_c/env_set_alloc.html">DB_ENV->set_alloc</a> for more
|
|
information), they are used to allocate the memory; otherwise, the
|
|
standard C library <b>malloc</b>(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.</p>
|
|
<p>In the presence of multiple threads or processes accessing an active
|
|
sequence, the information returned by DB_SEQUENCE->stat may be out-of-date.</p>
|
|
<p>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.</p>
|
|
<p>The statistics are stored in a structure of type DB_SEQUENCE_STAT. The
|
|
following fields will be filled in:</p>
|
|
<br>
|
|
<b>u_int32_t st_wait;</b><ul compact><li>The number of times a thread of control was forced to wait on the
|
|
handle mutex.</ul>
|
|
<b>u_int32_t st_nowait;</b><ul compact><li>The number of times that a thread of control was able to obtain handle
|
|
mutex without waiting.</ul>
|
|
<b>db_seq_t st_current;</b><ul compact><li>The current value of the sequence in the database.</ul>
|
|
<b>db_seq_t st_value;</b><ul compact><li>The current cached value of the sequence.</ul>
|
|
<b>db_seq_t st_last_value;</b><ul compact><li>The last cached value of the sequence.</ul>
|
|
<b>db_seq_t st_min;</b><ul compact><li>The minimum permitted value of the sequence.</ul>
|
|
<b>db_seq_t st_max;</b><ul compact><li>The maximum permitted value of the sequence.</ul>
|
|
<b>int32_t st_cache_size;</b><ul compact><li>The number of values that will be cached in this handle.</ul>
|
|
<b>u_int32_t st_flags;</b><ul compact><li>The flags value for the sequence.</ul>
|
|
<br>
|
|
<b>Parameters</b> <br>
|
|
<b>flags</b><ul compact><li>The <b>flags</b> parameter must be set by bitwise inclusively <b>OR</b>'ing together one or more
|
|
of the following values:
|
|
<br>
|
|
<b><a name="DB_STAT_CLEAR">DB_STAT_CLEAR</a></b><ul compact><li>Reset statistics after printing their values.</ul>
|
|
<br></ul>
|
|
<br>
|
|
<p>The DB_SEQUENCE->stat method may not be called before the <a href="../api_c/seq_open.html">DB_SEQUENCE->open</a> method has
|
|
been called.</p>
|
|
<p>The DB_SEQUENCE->stat method
|
|
returns a non-zero error value on failure
|
|
and 0 on success.
|
|
</p>
|
|
<hr size=1 noshade>
|
|
<b>Description: DB_SEQUENCE->stat_print</b>
|
|
<p>The DB_SEQUENCE->stat_print method prints diagnostic information to the output
|
|
channel described by the <a href="../api_c/env_set_msgfile.html">DB_ENV->set_msgfile</a> method.</p>
|
|
<b>Parameters</b> <br>
|
|
<b>flags</b><ul compact><li>The <b>flags</b> parameter must be set by bitwise inclusively <b>OR</b>'ing together one or more
|
|
of the following values:
|
|
<br>
|
|
<b><a name="DB_STAT_CLEAR">DB_STAT_CLEAR</a></b><ul compact><li>Reset statistics after printing their values.</ul>
|
|
<br></ul>
|
|
<br>
|
|
<hr size=1 noshade>
|
|
<br><b>Class</b>
|
|
<a href="../api_c/seq_class.html">DB_SEQUENCE</a>
|
|
<br><b>See Also</b>
|
|
<a href="../api_c/seq_list.html">Sequences and Related Methods</a>
|
|
</tt>
|
|
<table width="100%"><tr><td><br></td><td align=right>
|
|
<a href="../api_c/api_core.html"><img src="../images/api.gif" alt="API"></a><a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a>
|
|
</td></tr></table>
|
|
<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font>
|
|
</body>
|
|
</html>
|