2011-09-13 17:44:24 +00:00
|
|
|
|
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
|
|
|
|
|
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
|
|
|
|
|
<html xmlns="http://www.w3.org/1999/xhtml">
|
|
|
|
|
|
<head>
|
|
|
|
|
|
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
|
|
|
|
|
|
<title>Chapter 4. The DBT Handle</title>
|
|
|
|
|
|
<link rel="stylesheet" href="apiReference.css" type="text/css" />
|
|
|
|
|
|
<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
|
|
|
|
|
|
<link rel="start" href="index.html" title="Berkeley DB C API Reference" />
|
|
|
|
|
|
<link rel="up" href="index.html" title="Berkeley DB C API Reference" />
|
|
|
|
|
|
<link rel="prev" href="dbcset_priority.html" title="DBcursor->set_priority()" />
|
|
|
|
|
|
<link rel="next" href="DB_MULTIPLE_INIT.html" title="DB_MULTIPLE_INIT" />
|
|
|
|
|
|
</head>
|
|
|
|
|
|
<body>
|
|
|
|
|
|
<div xmlns="" class="navheader">
|
|
|
|
|
|
<div class="libver">
|
2012-11-14 21:35:20 +00:00
|
|
|
|
<p>Library Version 11.2.5.3</p>
|
2011-09-13 17:44:24 +00:00
|
|
|
|
</div>
|
|
|
|
|
|
<table width="100%" summary="Navigation header">
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<th colspan="3" align="center">Chapter 4.
|
|
|
|
|
|
The DBT Handle
|
|
|
|
|
|
</th>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td width="20%" align="left"><a accesskey="p" href="dbcset_priority.html">Prev</a> </td>
|
|
|
|
|
|
<th width="60%" align="center"> </th>
|
|
|
|
|
|
<td width="20%" align="right"> <a accesskey="n" href="DB_MULTIPLE_INIT.html">Next</a></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
</table>
|
|
|
|
|
|
<hr />
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<div class="chapter" lang="en" xml:lang="en">
|
|
|
|
|
|
<div class="titlepage">
|
|
|
|
|
|
<div>
|
|
|
|
|
|
<div>
|
|
|
|
|
|
<h2 class="title"><a id="dbt"></a>Chapter 4.
|
|
|
|
|
|
The DBT Handle
|
|
|
|
|
|
</h2>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<pre class="programlisting">#include <db.h>
|
|
|
|
|
|
|
|
|
|
|
|
typedef struct {
|
|
|
|
|
|
void *data;
|
|
|
|
|
|
u_int32_t size;
|
|
|
|
|
|
u_int32_t ulen;
|
|
|
|
|
|
u_int32_t dlen;
|
|
|
|
|
|
u_int32_t doff;
|
|
|
|
|
|
u_int32_t flags;
|
|
|
|
|
|
} DBT;
|
|
|
|
|
|
|
|
|
|
|
|
</pre>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
Storage and retrieval for the <a class="link" href="db.html" title="Chapter 2. The DB Handle">DB</a> access methods are
|
|
|
|
|
|
based on key/data pairs. Both key and data items are represented by
|
|
|
|
|
|
<span>
|
|
|
|
|
|
the DBT data structure. (The name DBT is a mnemonic for data base thang, and was used
|
|
|
|
|
|
because no one could think of a reasonable name that wasn't already in use somewhere
|
|
|
|
|
|
else.)
|
|
|
|
|
|
</span>
|
|
|
|
|
|
|
|
|
|
|
|
Key and data byte strings may refer to strings of zero length up to strings of essentially
|
|
|
|
|
|
unlimited length. See <a href="../../programmer_reference/am_misc_dbsizes.html" class="olink">Database limits</a> for
|
|
|
|
|
|
more information.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
All fields of the DBT structure that are not explicitly set should
|
|
|
|
|
|
be initialized to nul bytes before the first time the structure is
|
|
|
|
|
|
used. Do this by declaring the structure external or static, or by
|
|
|
|
|
|
calling the C library routine
|
|
|
|
|
|
<span class="bold"><strong>memset</strong></span>(3).
|
|
|
|
|
|
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
<span>
|
|
|
|
|
|
By default, the <span class="bold"><strong>flags</strong></span> structure element is expected to
|
|
|
|
|
|
be set to 0. In this default case,
|
|
|
|
|
|
</span>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
when the application is providing Berkeley DB a key or data item to store into the database,
|
|
|
|
|
|
Berkeley DB expects the <span class="bold"><strong>data</strong></span>
|
|
|
|
|
|
|
|
|
|
|
|
<span>
|
|
|
|
|
|
structure element
|
|
|
|
|
|
</span>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
to point to a byte string of <span class="bold"><strong>size</strong></span> bytes. When returning a
|
|
|
|
|
|
key/data item to the application, Berkeley DB will store into the <span class="bold"><strong>data</strong></span>
|
|
|
|
|
|
|
|
|
|
|
|
<span>
|
|
|
|
|
|
structure element
|
|
|
|
|
|
</span>
|
|
|
|
|
|
|
|
|
|
|
|
a pointer to a byte string of <span class="bold"><strong>size</strong></span> bytes,
|
|
|
|
|
|
and the memory to which the pointer refers will be
|
|
|
|
|
|
allocated and managed by Berkeley DB. Note that using the default flags
|
|
|
|
|
|
for returned <code class="classname">DBT</code>s is only compatible with
|
|
|
|
|
|
single threaded usage of Berkeley DB.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
The elements of the DBT structure are defined as follows:
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<div class="itemizedlist">
|
|
|
|
|
|
<ul type="disc">
|
|
|
|
|
|
<li>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
<span class="bold"><strong>void *data;</strong></span>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
A pointer to a byte string.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
<span class="bold"><strong>u_int32_t size;</strong></span>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
The length of <span class="bold"><strong>data</strong></span>, in bytes.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
<span class="bold"><strong>u_int32_t ulen;</strong></span>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
The size of the user's buffer (to which <span class="bold"><strong>data</strong></span> refers), in bytes. This
|
|
|
|
|
|
location is not written by the Berkeley DB functions.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
Set the byte size of the user-specified buffer.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
Note that applications can determine the length of a record by setting
|
|
|
|
|
|
the <code class="literal">ulen</code> field to 0 and checking the return value in the
|
|
|
|
|
|
<span class="bold"><strong>size</strong></span> field. See
|
|
|
|
|
|
the <code class="literal">DB_DBT_USERMEM</code> flag for more information.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
<span class="bold"><strong>u_int32_t dlen;</strong></span>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
<span>
|
|
|
|
|
|
The
|
|
|
|
|
|
</span>
|
|
|
|
|
|
|
|
|
|
|
|
length of the partial record being read or written by the
|
|
|
|
|
|
application, in bytes. See the <code class="literal">DB_DBT_PARTIAL</code>
|
|
|
|
|
|
flag for more information.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
<span class="bold"><strong>u_int32_t doff;</strong></span>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
<span>
|
|
|
|
|
|
The
|
|
|
|
|
|
</span>
|
|
|
|
|
|
|
|
|
|
|
|
offset of the partial record being read or written by the application,
|
|
|
|
|
|
in bytes. See the <code class="literal">DB_DBT_PARTIAL</code> flag for more information.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
<span class="bold"><strong>u_int32_t flags;</strong></span>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
The <span class="bold"><strong>flags</strong></span> parameter must be set to 0 or
|
|
|
|
|
|
by bitwise inclusively <span class="bold"><strong>OR</strong></span>'ing together
|
|
|
|
|
|
one or more of the following values:
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<span>
|
|
|
|
|
|
<div class="itemizedlist"><ul type="circle"><li><p><a id="dbt_DB_DBT_MALLOC"></a>
|
|
|
|
|
|
<code class="literal">DB_DBT_MALLOC</code>
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
When this flag is set, Berkeley DB will allocate memory
|
|
|
|
|
|
for the returned key or data item (using
|
|
|
|
|
|
<span class="bold"><strong>malloc</strong></span>(3), or
|
|
|
|
|
|
the user-specified malloc function), and return a
|
|
|
|
|
|
pointer to it in the
|
|
|
|
|
|
<span class="bold"><strong>data</strong></span> field of the key or data
|
|
|
|
|
|
<code class="literal">DBT</code>
|
|
|
|
|
|
structure. Because any allocated memory becomes the
|
|
|
|
|
|
responsibility of the calling application, the caller
|
|
|
|
|
|
must determine whether memory was allocated using the
|
|
|
|
|
|
returned value of the
|
|
|
|
|
|
<span class="bold"><strong>data</strong></span> field.
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
It is an error to specify more than one of
|
|
|
|
|
|
<code class="literal">DB_DBT_MALLOC</code>,
|
|
|
|
|
|
<code class="literal">DB_DBT_REALLOC</code>, and
|
|
|
|
|
|
<code class="literal">DB_DBT_USERMEM</code>.
|
|
|
|
|
|
</p></li><li><p><a id="dbt_DB_DBT_REALLOC"></a>
|
|
|
|
|
|
<code class="literal">DB_DBT_REALLOC</code>
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
When this flag is set Berkeley DB will allocate memory
|
|
|
|
|
|
for the returned key or data item (using
|
|
|
|
|
|
<span class="bold"><strong>realloc</strong></span>(3), or
|
|
|
|
|
|
the user-specified realloc function), and return a
|
|
|
|
|
|
pointer to it in the
|
|
|
|
|
|
<span class="bold"><strong>data</strong></span> field of the key or data DBT
|
|
|
|
|
|
structure. Because any allocated memory becomes the
|
|
|
|
|
|
responsibility of the calling application, the caller
|
|
|
|
|
|
must determine whether memory was allocated using the
|
|
|
|
|
|
returned value of the
|
|
|
|
|
|
<span class="bold"><strong>data</strong></span> field.
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
The difference between
|
|
|
|
|
|
<code class="literal">DB_DBT_MALLOC</code> and
|
|
|
|
|
|
<code class="literal">DB_DBT_REALLOC</code>
|
|
|
|
|
|
is that the latter will call
|
|
|
|
|
|
<span class="bold"><strong>realloc</strong></span>(3) instead of
|
|
|
|
|
|
<span class="bold"><strong>malloc</strong></span>(3),
|
|
|
|
|
|
so the allocated memory will be grown as
|
|
|
|
|
|
necessary instead of the application doing repeated
|
|
|
|
|
|
free/malloc calls.
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
It is an error to specify more than one of
|
|
|
|
|
|
<code class="literal">DB_DBT_MALLOC</code>,
|
|
|
|
|
|
<code class="literal">DB_DBT_REALLOC</code>, and
|
|
|
|
|
|
<code class="literal">DB_DBT_USERMEM</code>.
|
|
|
|
|
|
</p></li><li><p><a id="dbt_DB_DBT_USERMEM"></a>
|
|
|
|
|
|
<code class="literal">DB_DBT_USERMEM</code>
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
The <span class="emphasis"><em>data</em></span>
|
|
|
|
|
|
field of the key or data structure must refer
|
|
|
|
|
|
to memory that is at least
|
|
|
|
|
|
<span class="emphasis"><em>ulen</em></span>
|
|
|
|
|
|
bytes in length. If the
|
|
|
|
|
|
length of the requested item is less than or equal to
|
|
|
|
|
|
that number of bytes, the item is copied into the memory
|
|
|
|
|
|
to which the
|
|
|
|
|
|
<span class="emphasis"><em>data</em></span>
|
|
|
|
|
|
field refers. Otherwise, the
|
|
|
|
|
|
<span class="emphasis"><em>size</em></span>
|
|
|
|
|
|
field is set to the length needed for the requested
|
|
|
|
|
|
item, and the error
|
|
|
|
|
|
<code class="literal">DB_BUFFER_SMALL</code> is returned.
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
It is an error to specify more than one of
|
|
|
|
|
|
<code class="literal">DB_DBT_MALLOC</code>,
|
|
|
|
|
|
<code class="literal">DB_DBT_REALLOC</code>, and
|
|
|
|
|
|
<code class="literal">DB_DBT_USERMEM</code>.
|
|
|
|
|
|
</p></li></ul></div>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<div class="itemizedlist"><ul type="circle"><li><p><a id="dbt_DB_DBT_PARTIAL"></a>
|
|
|
|
|
|
<code class="literal">DB_DBT_PARTIAL</code>
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
Do partial retrieval or storage of an item. If the
|
|
|
|
|
|
calling application is doing a get, the
|
|
|
|
|
|
<span class="bold"><strong>dlen</strong></span> bytes
|
|
|
|
|
|
starting
|
|
|
|
|
|
<span class="bold"><strong>doff</strong></span>
|
|
|
|
|
|
bytes from the beginning of the retrieved
|
|
|
|
|
|
data record are returned as if they comprised the entire
|
|
|
|
|
|
record. If any or all of the specified bytes do not
|
|
|
|
|
|
exist in the record, the get is successful, and any
|
|
|
|
|
|
existing bytes are returned.
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
For example, if the data portion of a retrieved record
|
|
|
|
|
|
was 100 bytes, and a partial retrieval was done using a
|
|
|
|
|
|
DBT having a
|
|
|
|
|
|
<span class="bold"><strong>dlen</strong></span>
|
|
|
|
|
|
field of 20 and a
|
|
|
|
|
|
<span class="bold"><strong>doff</strong></span>
|
|
|
|
|
|
field of 85,
|
|
|
|
|
|
the get call would succeed, the
|
|
|
|
|
|
<span class="bold"><strong>data</strong></span>
|
|
|
|
|
|
field would refer
|
|
|
|
|
|
to the last 15 bytes of the record, and the
|
|
|
|
|
|
<span class="bold"><strong>size</strong></span>
|
|
|
|
|
|
field would be set to 15.
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
If the calling application is doing a put, the
|
|
|
|
|
|
<span class="bold"><strong>dlen</strong></span>
|
|
|
|
|
|
bytes starting
|
|
|
|
|
|
<span class="bold"><strong>doff</strong></span>
|
|
|
|
|
|
bytes from the beginning of the
|
|
|
|
|
|
specified key's data record are replaced by the data
|
|
|
|
|
|
specified by the
|
|
|
|
|
|
<span class="bold"><strong>data</strong></span>
|
|
|
|
|
|
and
|
|
|
|
|
|
<span class="bold"><strong>size</strong></span>
|
|
|
|
|
|
structure elements. If
|
|
|
|
|
|
<span class="bold"><strong>dlen</strong></span>
|
|
|
|
|
|
is smaller than
|
|
|
|
|
|
<span class="bold"><strong>size</strong></span>
|
|
|
|
|
|
the record will grow; if
|
|
|
|
|
|
<span class="bold"><strong>dlen</strong></span>
|
|
|
|
|
|
is larger than
|
|
|
|
|
|
<span class="bold"><strong>size</strong></span>
|
|
|
|
|
|
the record will shrink. If the
|
|
|
|
|
|
specified bytes do not exist, the record will be
|
|
|
|
|
|
extended using nul bytes as necessary, and the put call
|
|
|
|
|
|
will succeed.
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
It is an error to attempt a partial put using the
|
|
|
|
|
|
<a class="xref" href="dbput.html" title="DB->put()">DB->put()</a>
|
|
|
|
|
|
method in a database that supports duplicate
|
|
|
|
|
|
records. Partial puts in databases supporting duplicate
|
|
|
|
|
|
records must be done using a
|
|
|
|
|
|
<a class="xref" href="dbcput.html" title="DBcursor->put()">DBcursor->put()</a>
|
|
|
|
|
|
method.
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
It is an error to attempt a partial put with differing
|
|
|
|
|
|
<span class="bold"><strong>dlen</strong></span>
|
|
|
|
|
|
and
|
|
|
|
|
|
<span class="bold"><strong>size</strong></span>
|
|
|
|
|
|
values in Queue or Recno databases with
|
|
|
|
|
|
fixed-length records.
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
For example, if the data portion of a retrieved record
|
|
|
|
|
|
was 100 bytes, and a partial put was done using a DBT
|
|
|
|
|
|
having a
|
|
|
|
|
|
<span class="bold"><strong>dlen</strong></span>
|
|
|
|
|
|
field of 20, a
|
|
|
|
|
|
<span class="bold"><strong>doff</strong></span>
|
|
|
|
|
|
field of 85, and a
|
|
|
|
|
|
<span class="bold"><strong>size</strong></span>
|
|
|
|
|
|
field of 30, the resulting record would be 115
|
|
|
|
|
|
bytes in length, where the last 30 bytes would be those
|
|
|
|
|
|
specified by the put call.
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
This flag is ignored when used with the
|
|
|
|
|
|
<code class="literal">pkey</code> parameter on
|
|
|
|
|
|
<a class="link" href="dbget.html" title="DB->get()">DB->pget()</a> or
|
|
|
|
|
|
<a class="link" href="dbcget.html" title="DBcursor->get()">DBcursor->pget()</a>.
|
|
|
|
|
|
</p></li><li><p><a id="dbt_DB_DBT_APPMALLOC"></a>
|
|
|
|
|
|
<code class="literal">DB_DBT_APPMALLOC</code>
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
After an application-supplied callback routine passed to
|
|
|
|
|
|
either
|
|
|
|
|
|
<a class="xref" href="dbassociate.html" title="DB->associate()">DB->associate()</a>
|
|
|
|
|
|
or
|
|
|
|
|
|
<a class="xref" href="dbset_append_recno.html" title="DB->set_append_recno()">DB->set_append_recno()</a>
|
|
|
|
|
|
is executed, the
|
|
|
|
|
|
<span class="bold"><strong>data</strong></span>
|
|
|
|
|
|
field of a DBT may refer to memory allocated with
|
|
|
|
|
|
<span class="bold"><strong>malloc</strong></span>(3)
|
|
|
|
|
|
or
|
|
|
|
|
|
<span class="bold"><strong>realloc</strong></span>(3).
|
|
|
|
|
|
In that case,
|
|
|
|
|
|
the callback sets the
|
|
|
|
|
|
<code class="literal">DB_DBT_APPMALLOC</code>
|
|
|
|
|
|
flag in the DBT
|
|
|
|
|
|
so that Berkeley DB will call
|
|
|
|
|
|
<span class="bold"><strong>free</strong></span>(3)
|
|
|
|
|
|
to deallocate the
|
|
|
|
|
|
memory when it is no longer required.
|
|
|
|
|
|
</p></li><li><p><a id="dbt_DB_DBT_MULTIPLE"></a>
|
|
|
|
|
|
<code class="literal">DB_DBT_MULTIPLE</code>
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
Set in a secondary key creation callback routine passed
|
|
|
|
|
|
to
|
|
|
|
|
|
<a class="xref" href="dbassociate.html" title="DB->associate()">DB->associate()</a>
|
|
|
|
|
|
to indicate that multiple secondary
|
|
|
|
|
|
keys should be associated with the given primary
|
|
|
|
|
|
key/data pair. If set, the
|
|
|
|
|
|
<span class="bold"><strong>size</strong></span>
|
|
|
|
|
|
field indicates the
|
|
|
|
|
|
number of secondary keys and the
|
|
|
|
|
|
<span class="bold"><strong>data</strong></span>
|
|
|
|
|
|
field refers to an
|
|
|
|
|
|
array of that number of DBT structures.
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
The <code class="literal">DB_DBT_APPMALLOC</code> flag may be set on any of the DBT
|
|
|
|
|
|
structures to indicate that their
|
|
|
|
|
|
<span class="bold"><strong>data</strong></span>
|
|
|
|
|
|
field needs to be
|
|
|
|
|
|
freed.
|
|
|
|
|
|
</p></li><li><p><a id="dbt_DB_DBT_READONLY"></a>
|
|
|
|
|
|
<code class="literal">DB_DBT_READONLY</code>
|
|
|
|
|
|
</p><p>
|
|
|
|
|
|
When this flag is set Berkeley DB will not write
|
|
|
|
|
|
into the DBT. This may be set on key values in
|
|
|
|
|
|
cases where the key is a static string that cannot
|
|
|
|
|
|
be written and Berkeley DB might try to update it
|
|
|
|
|
|
because the application has set a user defined
|
|
|
|
|
|
comparison function.
|
|
|
|
|
|
</p></li></ul></div>
|
|
|
|
|
|
</span>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
</ul>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<div class="sect1" lang="en" xml:lang="en">
|
|
|
|
|
|
<div class="titlepage">
|
|
|
|
|
|
<div>
|
|
|
|
|
|
<div>
|
|
|
|
|
|
<h2 class="title" style="clear: both"><a id="dbtlist"></a>DBT and Bulk Operations</h2>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<div class="navtable">
|
|
|
|
|
|
<table border="1" width="80%">
|
|
|
|
|
|
<thead>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<th>DBT and Bulk Operations</th>
|
|
|
|
|
|
<th>Description</th>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
</thead>
|
|
|
|
|
|
<tbody>
|
2012-11-14 21:35:20 +00:00
|
|
|
|
<tr>
|
|
|
|
|
|
<td>
|
|
|
|
|
|
<a class="xref" href="dbsort_multiple.html" title="DB->sort_multiple()">DB->sort_multiple()</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td>Sort a set of DBTs</td>
|
|
|
|
|
|
</tr>
|
2011-09-13 17:44:24 +00:00
|
|
|
|
<tr>
|
|
|
|
|
|
<td>
|
|
|
|
|
|
<a class="xref" href="DB_MULTIPLE_INIT.html" title="DB_MULTIPLE_INIT">DB_MULTIPLE_INIT</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td>Initialize bulk get retrieval</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>
|
|
|
|
|
|
<a class="xref" href="DB_MULTIPLE_NEXT.html" title="DB_MULTIPLE_NEXT">DB_MULTIPLE_NEXT</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td>Next bulk get retrieval</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>
|
|
|
|
|
|
<a class="xref" href="DB_MULTIPLE_KEY_NEXT.html" title="DB_MULTIPLE_KEY_NEXT">DB_MULTIPLE_KEY_NEXT</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td>Next bulk get retrieval</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>
|
|
|
|
|
|
<a class="xref" href="DB_MULTIPLE_RECNO_NEXT.html" title="DB_MULTIPLE_RECNO_NEXT">DB_MULTIPLE_RECNO_NEXT</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td>Next bulk get retrieval</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>
|
|
|
|
|
|
<a class="xref" href="DB_MULTIPLE_WRITE_INIT.html" title="DB_MULTIPLE_WRITE_INIT">DB_MULTIPLE_WRITE_INIT</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td>Initialize a bulk buffer to hold key/data pairs</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>
|
|
|
|
|
|
<a class="xref" href="DB_MULTIPLE_WRITE_NEXT.html" title="DB_MULTIPLE_WRITE_NEXT">DB_MULTIPLE_WRITE_NEXT</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td>Append a data item to a bulk buffer</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>
|
|
|
|
|
|
<a class="xref" href="DB_MULTIPLE_RESERVE_NEXT.html" title="DB_MULTIPLE_RESERVE_NEXT">DB_MULTIPLE_RESERVE_NEXT</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td>Reserve space for a data item in a bulk buffer</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>
|
|
|
|
|
|
<a class="xref" href="DB_MULTIPLE_KEY_WRITE_NEXT.html" title="DB_MULTIPLE_KEY_WRITE_NEXT">DB_MULTIPLE_KEY_WRITE_NEXT</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td>Append a key / data pair to a bulk buffer</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>
|
|
|
|
|
|
<a class="xref" href="DB_MULTIPLE_KEY_RESERVE_NEXT.html" title="DB_MULTIPLE_KEY_RESERVE_NEXT">DB_MULTIPLE_KEY_RESERVE_NEXT</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td>Reserve space for a key / data pair in a bulk buffer</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>
|
|
|
|
|
|
<a class="xref" href="DB_MULTIPLE_RECNO_WRITE_INIT.html" title="DB_MULTIPLE_RECNO_WRITE_INIT">DB_MULTIPLE_RECNO_WRITE_INIT</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td>Initialize a bulk buffer to hold recno/data pairs</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>
|
|
|
|
|
|
<a class="xref" href="DB_MULTIPLE_RECNO_WRITE_NEXT.html" title="DB_MULTIPLE_RECNO_WRITE_NEXT">DB_MULTIPLE_RECNO_WRITE_NEXT</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td>Append a record number / data pair to a bulk buffer</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td>
|
|
|
|
|
|
<a class="xref" href="DB_MULTIPLE_RECNO_RESERVE_NEXT.html" title="DB_MULTIPLE_RECNO_RESERVE_NEXT">DB_MULTIPLE_RECNO_RESERVE_NEXT</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td>Reserve space for a record number / data pair in a bulk buffer</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
</tbody>
|
|
|
|
|
|
</table>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<div class="navfooter">
|
|
|
|
|
|
<hr />
|
|
|
|
|
|
<table width="100%" summary="Navigation footer">
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td width="40%" align="left"><a accesskey="p" href="dbcset_priority.html">Prev</a> </td>
|
|
|
|
|
|
<td width="20%" align="center"> </td>
|
|
|
|
|
|
<td width="40%" align="right"> <a accesskey="n" href="DB_MULTIPLE_INIT.html">Next</a></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td width="40%" align="left" valign="top">DBcursor->set_priority() </td>
|
|
|
|
|
|
<td width="20%" align="center">
|
|
|
|
|
|
<a accesskey="h" href="index.html">Home</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td width="40%" align="right" valign="top"> DB_MULTIPLE_INIT</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
</table>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</body>
|
|
|
|
|
|
</html>
|
