rm_ch2.htm

db.* (pronounced dee-be star) is an advanced, high performance, small footprint embedded database fo

<p><i>fileid</i><br>
An identifier used as a reference for the specified file.</p>
<p><i>filename</i><br>
A string enclosed in double quotes (" ") that names the file.</p>
<p><i>recname</i><br>
An identifier that names a record type.</p>
<p><i>keyname</i><br>
The name of a key field. When listed in a key file statement,
<i>keyname</i> can have a prefix identifying the record type
(necessary when using the -d option). The format is
<i>recname.keyname</i>.</p>
<p><i>fldname</i><br>
An identifier that names a data field.</p>
<p><i>dim</i><br>
A number that specifies the size of an array field dimension.</p>
<p><i>setname</i><br>
An identifier that names a set.</p>
<p align="center"><b><u>ddlp Keywords</u></b> (<i>not</i> case
sensitive)</p>
<table cellspacing="0" border="0" cellpadding="7" width="542">
<tr>
<td width="26%" valign="top">
<p><font size="2">#define</font></p>
</td>
<td width="22%" valign="top">
<p><font size="2">last</font></p>
</td>
<td width="27%" valign="top">
<p><font size="2">database</font></p>
</td>
<td width="25%" valign="top">
<p><font size="2">set</font></p>
</td>
</tr>
<tr>
<td width="26%" valign="top">
<p><font size="2">asc</font></p>
</td>
<td width="22%" valign="top">
<p><font size="2">long</font></p>
</td>
<td width="27%" valign="top">
<p><font size="2">db_addr</font></p>
</td>
<td width="25%" valign="top">
<p><font size="2">sets</font></p>
</td>
</tr>
<tr>
<td width="26%" valign="top">
<p><font size="2">ascending</font></p>
</td>
<td width="22%" valign="top">
<p><font size="2">member</font></p>
</td>
<td width="27%" valign="top">
<p><font size="2">desc</font></p>
</td>
<td width="25%" valign="top">
<p><font size="2">static</font></p>
</td>
</tr>
<tr>
<td width="26%" valign="top">
<p><font size="2">bitmap</font></p>
</td>
<td width="22%" valign="top">
<p><font size="2">next</font></p>
</td>
<td width="27%" valign="top">
<p><font size="2">descending</font></p>
</td>
<td width="25%" valign="top">
<p><font size="2">struct</font></p>
</td>
</tr>
<tr>
<td width="26%" valign="top">
<p><font size="2">blob</font></p>
</td>
<td width="22%" valign="top">
<p><font size="2">opt</font></p>
</td>
<td width="27%" valign="top">
<p><font size="2">directref</font></p>
</td>
<td width="25%" valign="top">
<p><font size="2">timestamp</font></p>
</td>
</tr>
<tr>
<td width="26%" valign="top">
<p><font size="2">by</font></p>
</td>
<td width="22%" valign="top">
<p><font size="2">optional</font></p>
</td>
<td width="27%" valign="top">
<p><font size="2">double</font></p>
</td>
<td width="25%" valign="top">
<p><font size="2">thru</font></p>
</td>
</tr>
<tr>
<td width="26%" valign="top">
<p><font size="2">char</font></p>
</td>
<td width="22%" valign="top">
<p><font size="2">order</font></p>
</td>
<td width="27%" valign="top">
<p><font size="2">file</font></p>
</td>
<td width="25%" valign="top">
<p><font size="2">typedef</font></p>
</td>
</tr>
<tr>
<td width="26%" valign="top">
<p><font size="2">compound</font></p>
</td>
<td width="22%" valign="top">
<p><font size="2">owner</font></p>
</td>
<td width="27%" valign="top">
<p><font size="2">first</font></p>
</td>
<td width="25%" valign="top">
<p><font size="2">unique</font></p>
</td>
</tr>
<tr>
<td width="26%" valign="top">
<p><font size="2">const</font></p>
</td>
<td width="22%" valign="top">
<p><font size="2">record</font></p>
</td>
<td width="27%" valign="top">
<p><font size="2">key</font></p>
</td>
<td width="25%" valign="top">
<p><font size="2">unsigned</font></p>
</td>
</tr>
<tr>
<td width="26%" valign="top">
<p><font size="2">contains</font></p>
</td>
<td width="22%" valign="top">
<p><font size="2">records</font></p>
</td>
<td width="27%" valign="top">
<p><font size="2">float</font></p>
</td>
<td width="25%" valign="top">
<p><font size="2">varilen</font></p>
</td>
</tr>
<tr>
<td width="26%" valign="top">
<p><font size="2">data</font></p>
</td>
<td width="22%" valign="top">
<p><font size="2">relatedto</font></p>
</td>
<td width="27%" valign="top">
<p><font size="2">int</font></p>
</td>
<td width="25%" valign="top">&nbsp;</td>
</tr>
</table>
<p><font size="2">&nbsp;</font></p>
<hr>
<h3><a name="ida" id="ida"></a>ida</h3>
<p><font size="2">Interactive Database Access utility</font></p>
<h4>Prototype</h4>
<pre>
<font color=
"#0000FF">ida [-m<i>x</i>] [[-s | -x | -o] [-t] <i>dbname</i>]</font>
</pre>
<h4>Description</h4>
<p><font size="2">The Interactive Database Access utility,
<b>ida</b>, is a menu-driven, screen-oriented utility that can be
used to retrieve, enter, modify, or delete any information or set
relationships stored in a <b><i>db.*</i></b> database. The utility
is fully described in Chapter 8, "Interactive Database Access
Utility (<b>ida</b>)," of the <b><i>db.*</i></b> <i>User's
Guide</i>. If database <i>dbname</i> is supplied, it will be opened
in exclusive access mode unless another open mode option is
specified.</font></p>
<h4>Options</h4>
<p><font size="2">-m<i>x</i><br>
Selects a lock manager type. See the <b><i>db.*</i></b>
<i>Multi-User Guide</i> for details.</font></p>
<p>-s<br>
Opens database <i>dbname</i> in shared access mode.</p>
<p>-x<br>
Opens database <i>dbname</i> in exclusive access mode
(default).</p>
<p>-o<br>
Opens database <i>dbname</i> in one-user only mode.</p>
<p>-t<br>
Enables an S_DEBUG <b>dberr</b> interrupt call (which prompts the
user for a return) just after a log file has been written and prior
to a transaction commit. The purpose is to provide the ability to
easily test automatic recovery using <b>ida</b>, by allowing the
user to abort the program at the prompt.</p>
<p>&nbsp;</p>
<hr>
<h3><a name="initdb" id="initdb"></a>initdb</h3>
<p><font size="2">Database initialization utility</font></p>
<h4>Prototype</h4>
<pre>
<font color="#0000FF">initdb [-y] <i>dbname</i></font>
</pre>
<h4>Description</h4>
<p><font size="2">The <b>initdb</b> utility initializes the data
and key files in database <i>dbname</i>. A database must be
initialized before any data can be stored in it. If the data and
key files exist, the utility displays the names of the database
files and prompts you for confirmation. If you reply with a "y",
the files are reinitialized; otherwise, the utility terminates. If
the -y option is specified, initialization proceeds without the
display of the file names and confirmation prompt.</font></p>
<blockquote><b><i>Warning:</i></b> This utility will delete all
existing data in the database.</blockquote>
<h4>Options</h4>
<p><font size="2">-y<br>
Re-initializes database files without displaying the confirmation
prompt.</font></p>
<p>&nbsp;</p>
<hr>
<h3><a name="keybuild" id="keybuild"></a>keybuild</h3>
<p><font size="2">Key file build utility</font></p>
<h4>Prototype</h4>
<pre>
<font color="#0000FF">keybuild [-p#] <i>dbname</i></font>
</pre>
<h4>Description</h4>
<p><font size="2">The <b>keybuild</b> utility rebuilds all key
files for the database <i>dbname</i>. Rebuilding key files is a
two-step process. First, the file is reinitialized. Then, each
record is sequentially read from each data file record, and each
key file is re-created from the record contents.</font></p>
<p>This utility can be used to re-create the key files when
<b>dbcheck</b> reports a database inconsistency. The utility can
also construct new key files after you have added or removed key
attributes from fields in your DDL specification. For example, if
you make an existing key field a non-key, and change a non-key to a
key field in your DDL, you can run <b>keybuild</b> to rebuild the
key files for the new schema. You can also use <b>keybuild</b> to
reassign key fields to different key files.</p>
<h4>Options</h4>
<p><font size="2">-p#<br>
Causes # pages to be used for the <b><i>db.*</i></b>
cache.</font></p>
<p>&nbsp;</p>
<hr>
<h3><a name="keydump" id="keydump"></a>keydump</h3>
<p><font size="2">Key file dump utility</font></p>
<h4>Prototype</h4>
<pre>
<font color=
"#0000FF">keydump [-h] <i>dbname</i> <i>keyfile</i></font>
</pre>
<h4>Description</h4>
<p><font size="2">The <b>keydump</b> utility displays a formatted
dump of key file <i>keyfile</i> in database <i>dbname</i>. If the
-h option is specified, the key values are printed in hexadecimal;
otherwise, the contents are displayed as formatted for data type of
the key field. The report is written to file <b>stdout</b> and can
be redirected as needed.</font></p>
<p>The B-tree organization of a <b><i>db.*</i></b> key file is
described in section 14.2.3, "Key File Organization," of the
<b><i>db.*</i></b> <i>User's Guide</i>. This utility can assist you
in learning how these files are structured.</p>
<h4>Options</h4>
<p><font size="2">-h<br>
Display key values in hexadecimal.</font></p>
<p>&nbsp;</p>
<hr>
<h3><a name="keypack" id="keypack"></a>keypack</h3>
<p><font size="2">Key file packing utility</font></p>
<h4>Prototype</h4>
<pre>
<font color=
"#0000FF">keypack [-u<i>num</i>] [-o|-x] [-t <i>path</i>] [-b <i>path</i>] [-k <i>path</i>] [-p<i>num</i>] [-m<i>x</i>] <i>dbname</i> [<i>keyfile</i>]</font>
</pre>
<h4>Description</h4>
<p><font size="2">This utility fills the B-tree nodes in a key file
(or all key files if <i>keyfile</i> is not specified), reducing the
number of nodes required in the B-tree. A B-tree node, created by
the <b><i>db.*</i></b> runtime library, will be at least half full,
and will have at least one empty key slot. (See section 14.2.3,
"Key File Organization," of the <b><i>db.*</i></b> <i>Users
Guide</i>.) The normal fill level in a B-tree is between 50% and
95%.</font></p>
<p>The utility can create B-tree nodes that are nearly 100% full.
However, if a B-tree is packed, the nodes will be split almost
immediately as more keys are added. For this reason, the
<b>keypack</b> utility is beneficial when used on key files that
are not going to be changed. Any database that is loaded for use by
read-only applications should have its key files packed.</p>
<h4>Options</h4>
<p><font size="2">-u<i>num</i><br>
Specifies the number of key slots to leave empty. Default is 1. If
<i>num</i> is 0, the resulting key files will only contain key
fields of static record types and cannot be modified.</font></p>
<p>-o<br>
Opens the database in one-user mode (default).</p>
<p>-x<br>
Opens the database in exclusive access mode.</p>
<p>-t <i>path</i><br>
Specifies the location of the temporary packed key file. When
finished, the original key file is deleted and the temporary packed
key file is renamed to the original key file name. If <i>path</i>
specifies a different drive, then <b>keypack</b> moves the
temporary packed key file to the device containing the original key
file. By default, the current directory is used.</p>
<p>-b <i>path</i><br>
Specifies the path to where a backup of the original key files will
be copied.</p>
<p>-k <i>path</i><br>
Specifies the path to where the packed key files will be placed.
The original key files do not change or move. This option overrides
both -t and -b.</p>
<p>-p<i>num</i><br>
Sets pages in the <b><i>db.*</i></b> cache to <i>num</i>.</p>
<p>-m<i>x</i><br>
Selects a lock manager type. See the <b><i>db.*</i></b>
<i>Multi-User Guide</i> for details.</p>
<p>&nbsp;</p>
<hr>
<h3><a name="prdbd" id="prdbd"></a>prdbd</h3>
<p><font size="2">Dictionary print utility</font></p>
<h4>Prototype</h4>
<pre>
<font color="#0000FF">prdbd [-c] <i>dbname</i></font>
</pre>
<h4>Description</h4>
<p><font size="2">This utility displays the contents of the
database dictionary file<i>,</i> &lt;<b>dbname</b>&gt;<b>.dbd</b>,
for database <i>dbname</i>. The utility will report the default
database page size and each entry in the file table, record table,
field table, set table, member table, sort field table, and key
table that constitutes the internal form of the <b><i>db.*</i></b>
database dictionary. The report is written to <b>stdout</b> and can
be redirected as desired.</font></p>
<p>The utility prints symbolic names wherever possible. If you want
the record, set, and field numbers only, use the -c option.</p>
<p>Section 14.3, "Database Dictionary Table Structure," of the
<b><i>db.*</i></b> <i>User's Guide</i> describes in detail the
organization of a <b><i>db.*</i></b> database dictionary. If
required by the application, this utility will help you understand
and make use of the dictionary in your own applications, probably
through the <b>d_internals</b> function.</p>
<h4>Options</h4>
<p><font size="2">None.</font></p>
<p><a href="RM_Ch3.htm">Next Page</a></p>
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