1<!--$Id: env_set_lk_max_locks.so,v 10.23 2004/09/28 15:04:20 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: DB_ENV->set_lk_max_locks</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>DB_ENV->set_lk_max_locks</b> 14</td> 15<td align=right> 16<a href="../api_c/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.h> 23<p> 24int 25DB_ENV->set_lk_max_locks(DB_ENV *dbenv, u_int32_t max); 26<p> 27int 28DB_ENV->get_lk_max_locks(DB_ENV *dbenv, u_int32_t *lk_maxp); 29</pre></b> 30<hr size=1 noshade> 31<b>Description: DB_ENV->set_lk_max_locks</b> 32<p>Set the maximum number of locks supported by the Berkeley DB environment. 33This value is used by <a href="../api_c/env_open.html">DB_ENV->open</a> to estimate how much space to 34allocate for various lock-table data structures. The default value is 351000 locks. For specific information on configuring the size of the lock 36subsystem, see <a href="../ref/lock/max.html">Configuring locking: 37sizing the system</a>.</p> 38<p>The database environment's maximum number of locks may also be configured using the 39environment's <a href="../ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> file. The syntax of the entry in that 40file is a single line with the string "set_lk_max_locks", one or more whitespace 41characters, and the number of locks. 42Because the <a href="../ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> file is read when the database environment 43is opened, it will silently overrule configuration done before that 44time.</p> 45<p>The DB_ENV->set_lk_max_locks method configures a database environment, not only operations 46performed using the specified <a href="../api_c/env_class.html">DB_ENV</a> handle.</p> 47<p>The DB_ENV->set_lk_max_locks method may not be called after the <a href="../api_c/env_open.html">DB_ENV->open</a> method is 48called. 49If the database environment already exists when 50<a href="../api_c/env_open.html">DB_ENV->open</a> is called, the information specified to DB_ENV->set_lk_max_locks 51will be ignored. 52</p> 53<p>The DB_ENV->set_lk_max_locks method 54returns a non-zero error value on failure 55and 0 on success. 56</p> 57<b>Parameters</b> <br> 58 <b>max</b><ul compact><li>The <b>max</b> parameter is the maximum number of locks supported by 59the Berkeley DB environment.</ul> 60<br> 61<br><b>Errors</b> 62<p>The DB_ENV->set_lk_max_locks method 63may fail and return one of the following non-zero errors:</p> 64<br> 65<b>EINVAL</b><ul compact><li>If the method was called after <a href="../api_c/env_open.html">DB_ENV->open</a> was called; or if an 66invalid flag value or parameter was specified.</ul> 67<br> 68<hr size=1 noshade> 69<b>Description: DB_ENV->get_lk_max_locks</b> 70<p>The DB_ENV->get_lk_max_locks method returns the maximum number of locks.</p> 71<p>The DB_ENV->get_lk_max_locks method may be called at any time during the life of the 72application.</p> 73<p>The DB_ENV->get_lk_max_locks method 74returns a non-zero error value on failure 75and 0 on success. 76</p> 77<b>Parameters</b> <br> 78 <b>lk_maxp</b><ul compact><li>The DB_ENV->get_lk_max_locks method returns the 79maximum number of locks in <b>lk_maxp</b>.</ul> 80<br> 81<hr size=1 noshade> 82<br><b>Class</b> 83<a href="../api_c/env_class.html">DB_ENV</a>, <a href="../api_c/lock_class.html">DB_LOCK</a> 84<br><b>See Also</b> 85<a href="../api_c/lock_list.html">Locking Subsystem and Related Methods</a> 86</tt> 87<table width="100%"><tr><td><br></td><td align=right> 88<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> 89</td></tr></table> 90<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 91</body> 92</html> 93
