1<!--$Id: seq_stat.so,v 1.9 2007/06/22 16:57:17 bostic Exp $--> 2<!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> 3<!--See the file LICENSE for redistribution information.--> 4<html> 5<head> 6<title>Berkeley DB: DbSequence::stat</title> 7<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> 8<meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> 9</head> 10<body bgcolor=white> 11<table width="100%"><tr valign=top> 12<td> 13<b>DbSequence::stat</b> 14</td> 15<td align=right> 16<a href="../api_cxx/api_core.html"><img src="../images/api.gif" alt="API"></a> 17<a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a></td> 18</tr></table> 19<hr size=1 noshade> 20<tt> 21<b><pre> 22#include <db_cxx.h> 23<p> 24int 25Db::stat(void *sp, u_int32_t flags); 26<p> 27int 28Db::stat_print(u_int32_t flags); 29</pre></b> 30<hr size=1 noshade> 31<b>Description: DbSequence::stat</b> 32<p>The DbSequence::stat method creates a statistical structure and copies a 33pointer to it into user-specified memory locations. Specifically, if 34<b>sp</b> is non-NULL, a pointer to the statistics for the database are 35copied into the memory location to which it refers.</p> 36<p>Statistical structures are stored in allocated memory. If application-specific allocation 37routines have been declared (see <a href="../api_cxx/env_set_alloc.html">DbEnv::set_alloc</a> for more 38information), they are used to allocate the memory; otherwise, the 39standard C library <b>malloc</b>(3) is used. The caller is 40responsible for deallocating the memory. To deallocate the memory, free 41the memory reference; references inside the returned memory need not be 42individually freed.</p> 43<p>In the presence of multiple threads or processes accessing an active 44sequence, the information returned by DbSequence::stat may be out-of-date.</p> 45<p>The DbSequence::stat method cannot be transaction-protected. For this reason, 46it should be called in a thread of control that has no open cursors or 47active transactions.</p> 48<p>The statistics are stored in a structure of type DB_SEQUENCE_STAT. The 49following fields will be filled in:</p> 50<br> 51<b>u_int32_t st_wait;</b><ul compact><li>The number of times a thread of control was forced to wait on the 52handle mutex.</ul> 53<b>u_int32_t st_nowait;</b><ul compact><li>The number of times that a thread of control was able to obtain handle 54mutex without waiting.</ul> 55<b>db_seq_t st_current;</b><ul compact><li>The current value of the sequence in the database.</ul> 56<b>db_seq_t st_value;</b><ul compact><li>The current cached value of the sequence.</ul> 57<b>db_seq_t st_last_value;</b><ul compact><li>The last cached value of the sequence.</ul> 58<b>db_seq_t st_min;</b><ul compact><li>The minimum permitted value of the sequence.</ul> 59<b>db_seq_t st_max;</b><ul compact><li>The maximum permitted value of the sequence.</ul> 60<b>int32_t st_cache_size;</b><ul compact><li>The number of values that will be cached in this handle.</ul> 61<b>u_int32_t st_flags;</b><ul compact><li>The flags value for the sequence.</ul> 62<br> 63<b>Parameters</b> <br> 64 <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 65of the following values: 66<br> 67<b><a name="DB_STAT_CLEAR">DB_STAT_CLEAR</a></b><ul compact><li>Reset statistics after printing their values.</ul> 68<br></ul> 69<br> 70<p>The DbSequence::stat method may not be called before the <a href="../api_cxx/seq_open.html">DbSequence::open</a> method has 71been called.</p> 72<p>The DbSequence::stat method 73either returns a non-zero error value 74or throws an exception that encapsulates a non-zero error value on 75failure, and returns 0 on success. 76</p> 77<hr size=1 noshade> 78<b>Description: DbSequence::stat_print</b> 79<p>The DbSequence::stat_print method prints diagnostic information to the output 80channel described by the <a href="../api_cxx/env_set_msgfile.html">DbEnv::set_msgfile</a> method.</p> 81<b>Parameters</b> <br> 82 <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 83of the following values: 84<br> 85<b><a name="DB_STAT_CLEAR">DB_STAT_CLEAR</a></b><ul compact><li>Reset statistics after printing their values.</ul> 86<br></ul> 87<br> 88<hr size=1 noshade> 89<br><b>Class</b> 90<a href="../api_cxx/seq_class.html">DbSequence</a> 91<br><b>See Also</b> 92<a href="../api_cxx/seq_list.html">Sequences and Related Methods</a> 93</tt> 94<table width="100%"><tr><td><br></td><td align=right> 95<a href="../api_cxx/api_core.html"><img src="../images/api.gif" alt="API"></a><a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a> 96</td></tr></table> 97<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 98</body> 99</html> 100
