<!--$Id: ops.so,v 10.22 2002/08/30 20:01:36 bostic Exp $--> <!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> <!--See the file LICENSE for redistribution information.--> <html> <head> <title>Berkeley DB Reference Guide: Access method operations</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><dl><dt>Berkeley DB Reference Guide:<dd>Access Methods</dl></b></td> <td align=right><a href="../am_conf/renumber.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../am/open.html"><img src="../../images/next.gif" alt="Next"></a> </td></tr></table> <p align=center><b>Access method operations</b></p> <p>Once a database handle has been created using <a href="../../api_c/db_class.html">db_create</a>, there are several standard access method operations. Each of these operations is performed using a method referred to by the returned handle. Generally, the database will be opened using <a href="../../api_c/db_open.html">DB->open</a>. If the database is from an old release of Berkeley DB, it may need to be upgraded to the current release before it is opened using <a href="../../api_c/db_upgrade.html">DB->upgrade</a>.</p> <p>Once a database has been opened, records may be retrieved (<a href="../../api_c/db_get.html">DB->get</a>), stored (<a href="../../api_c/db_put.html">DB->put</a>), and deleted (<a href="../../api_c/db_del.html">DB->del</a>).</p> <p>Additional operations supported by the database handle include statistics (<a href="../../api_c/db_stat.html">DB->stat</a>), truncation (<a href="../../api_c/db_truncate.html">DB->truncate</a>), version upgrade (<a href="../../api_c/db_upgrade.html">DB->upgrade</a>), verification and salvage (<a href="../../api_c/db_verify.html">DB->verify</a>), flushing to a backing file (<a href="../../api_c/db_sync.html">DB->sync</a>), and association of secondary indices (<a href="../../api_c/db_associate.html">DB->associate</a>). Database handles are eventually closed using <a href="../../api_c/db_close.html">DB->close</a>.</p> <!--$Id: m4.methods,v 1.14 2007/07/12 18:27:42 bostic Exp $--> <table border=1 align=center> <tr><th>Database Operations</th><th>Description</th></tr> <!--Db::--><tr><td><a href="../../api_c/db_class.html">db_create</a></td><td>Create a database handle</td></tr> <!--Db::associate--><tr><td><a href="../../api_c/db_associate.html">DB->associate</a></td><td>Associate a secondary index</td></tr> <!--Db::close--><tr><td><a href="../../api_c/db_close.html">DB->close</a></td><td>Close a database</td></tr> <!--Db::compact--><tr><td><a href="../../api_c/db_compact.html">DB->compact</a></td><td>Compact a database</td></tr> <!--Db::cursor--><tr><td><a href="../../api_c/db_cursor.html">DB->cursor</a></td><td>Create a cursor</td></tr> <!--Db::del--><tr><td><a href="../../api_c/db_del.html">DB->del</a></td><td>Delete items from a database</td></tr> <!--Db::err--><tr><td><a href="../../api_c/db_err.html">DB->err</a>, <a href="../../api_c/db_err.html">DB->errx</a></td><td>Error message</td></tr> <!--Db::exists--><tr><td><a href="../../api_c/db_exists.html">DB->exists</a></td><td>Return if an item appears in a database</td></tr> <!--Db::fd--><tr><td><a href="../../api_c/db_fd.html">DB->fd</a></td><td>Return a file descriptor from a database</td></tr> <!--Db::get--><tr><td><a href="../../api_c/db_get.html">DB->get</a>, <a href="../../api_c/db_get.html">DB->pget</a></td><td>Get items from a database</td></tr> <!--Db::get_byteswapped--><tr><td><a href="../../api_c/db_get_byteswapped.html">DB->get_byteswapped</a></td><td>Return if the underlying database is in host order</td></tr> <!--Db::get_type--><tr><td><a href="../../api_c/db_get_type.html">DB->get_type</a></td><td>Return the database type</td></tr> <!--Db::join--><tr><td><a href="../../api_c/db_join.html">DB->join</a></td><td>Perform a database join on cursors</td></tr> <!--Db::key_range--><tr><td><a href="../../api_c/db_key_range.html">DB->key_range</a></td><td>Return estimate of key location</td></tr> <!--Db::open--><tr><td><a href="../../api_c/db_open.html">DB->open</a></td><td>Open a database</td></tr> <!--Db::put--><tr><td><a href="../../api_c/db_put.html">DB->put</a></td><td>Store items into a database</td></tr> <!--Db::remove--><tr><td><a href="../../api_c/db_remove.html">DB->remove</a></td><td>Remove a database</td></tr> <!--Db::rename--><tr><td><a href="../../api_c/db_rename.html">DB->rename</a></td><td>Rename a database</td></tr> <!--Db::set_priority--><tr><td><a href="../../api_c/db_set_priority.html">DB->set_priority</a></td><td>Set cache page priority</td></tr> <!--Db::stat--><tr><td><a href="../../api_c/db_stat.html">DB->stat</a>, <a href="../../api_c/db_stat.html">DB->stat_print</a></td><td>Database statistics</td></tr> <!--Db::sync--><tr><td><a href="../../api_c/db_sync.html">DB->sync</a></td><td>Flush a database to stable storage</td></tr> <!--Db::truncate--><tr><td><a href="../../api_c/db_truncate.html">DB->truncate</a></td><td>Empty a database</td></tr> <!--Db::upgrade--><tr><td><a href="../../api_c/db_upgrade.html">DB->upgrade</a></td><td>Upgrade a database</td></tr> <!--Db::verify--><tr><td><a href="../../api_c/db_verify.html">DB->verify</a></td><td>Verify/salvage a database</td></tr> <tr><th>Database Configuration</th><th><br></th></tr> <!--Db::set_alloc--><tr><td><a href="../../api_c/db_set_alloc.html">DB->set_alloc</a></td><td>Set local space allocation functions</td></tr> <!--Db::set_cachesize--><tr><td><a href="../../api_c/db_set_cachesize.html">DB->set_cachesize</a></td><td>Set the database cache size</td></tr> <!--Db::set_dup_compare--><tr><td><a href="../../api_c/db_set_dup_compare.html">DB->set_dup_compare</a></td><td>Set a duplicate comparison function</td></tr> <!--Db::set_encrypt--><tr><td><a href="../../api_c/db_set_encrypt.html">DB->set_encrypt</a></td><td>Set the database cryptographic key</td></tr> <!--Db::set_errcall--><tr><td><a href="../../api_c/db_set_errcall.html">DB->set_errcall</a>, <a href="../../api_c/db_set_msgcall.html">DB->set_msgcall</a></td><td>Set error and informational message callback</td></tr> <!--Db::set_errfile--><tr><td><a href="../../api_c/db_set_errfile.html">DB->set_errfile</a>, <a href="../../api_c/db_set_msgfile.html">DB->set_msgfile</a></td><td>Set error and informational message FILE</td></tr> <!--Db::set_error_stream--> <!--Db::set_errpfx--><tr><td><a href="../../api_c/db_set_errpfx.html">DB->set_errpfx</a></td><td>Set error message prefix</td></tr> <!--Db::set_feedback--><tr><td><a href="../../api_c/db_set_feedback.html">DB->set_feedback</a></td><td>Set feedback callback</td></tr> <!--Db::set_flags--><tr><td><a href="../../api_c/db_set_flags.html">DB->set_flags</a></td><td>General database configuration</td></tr> <!--Db::set_lorder--><tr><td><a href="../../api_c/db_set_lorder.html">DB->set_lorder</a></td><td>Set the database byte order</td></tr> <!--Db::set_pagesize--><tr><td><a href="../../api_c/db_set_pagesize.html">DB->set_pagesize</a></td><td>Set the underlying database page size</td></tr> <tr><th>Btree/Recno Configuration</th><th><br></th></tr> <!--Db::set_append_recno--><tr><td><a href="../../api_c/db_set_append_recno.html">DB->set_append_recno</a></td><td>Set record append callback</td></tr> <!--Db::set_bt_compare--><tr><td><a href="../../api_c/db_set_bt_compare.html">DB->set_bt_compare</a></td><td>Set a Btree comparison function</td></tr> <!--Db::set_bt_minkey--><tr><td><a href="../../api_c/db_set_bt_minkey.html">DB->set_bt_minkey</a></td><td>Set the minimum number of keys per Btree page</td></tr> <!--Db::set_bt_prefix--><tr><td><a href="../../api_c/db_set_bt_prefix.html">DB->set_bt_prefix</a></td><td>Set a Btree prefix comparison function</td></tr> <!--Db::set_re_delim--><tr><td><a href="../../api_c/db_set_re_delim.html">DB->set_re_delim</a></td><td>Set the variable-length record delimiter</td></tr> <!--Db::set_re_len--><tr><td><a href="../../api_c/db_set_re_len.html">DB->set_re_len</a></td><td>Set the fixed-length record length</td></tr> <!--Db::set_re_pad--><tr><td><a href="../../api_c/db_set_re_pad.html">DB->set_re_pad</a></td><td>Set the fixed-length record pad byte</td></tr> <!--Db::set_re_source--><tr><td><a href="../../api_c/db_set_re_source.html">DB->set_re_source</a></td><td>Set the backing Recno text file</td></tr> <tr><th>Hash Configuration</th><th><br></th></tr> <!--Db::set_h_compare--><tr><td><a href="../../api_c/db_set_h_compare.html">DB->set_h_compare</a></td><td>Set a Hash comparison function</td></tr> <!--Db::set_h_ffactor--><tr><td><a href="../../api_c/db_set_h_ffactor.html">DB->set_h_ffactor</a></td><td>Set the Hash table density</td></tr> <!--Db::set_h_hash--><tr><td><a href="../../api_c/db_set_h_hash.html">DB->set_h_hash</a></td><td>Set a hashing function</td></tr> <!--Db::set_h_nelem--><tr><td><a href="../../api_c/db_set_h_nelem.html">DB->set_h_nelem</a></td><td>Set the Hash table size</td></tr> <tr><th>Queue Configuration</th><th><br></th></tr> <!--Db::set_q_extentsize--><tr><td><a href="../../api_c/db_set_q_extentsize.html">DB->set_q_extentsize</a></td><td>Set Queue database extent size</td></tr> </table> <table width="100%"><tr><td><br></td><td align=right><a href="../am_conf/renumber.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../am/open.html"><img src="../../images/next.gif" alt="Next"></a> </td></tr></table> <p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> </body> </html>