Closing Bug #19077

#maybe someone will analyse which libraries fail and wich work (e.g. wait).


git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@102748 c90b9560-bf6c-de11-be94-00142212c4b1

reference/dba/functions/dba-open.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.3 $ -->
+<!-- $Revision: 1.4 $ -->
 <!-- splitted from ./en/functions/dba.xml, last change in rev 1.2 -->
   <refentry id="function.dba-open">
    <refnamediv>
@@ -9,7 +9,7 @@
    <refsect1>
     <title>Description</title>
      <methodsynopsis>
-      <type>resource</type><methodname>dba_open</methodname>
+      <type>resource|false</type><methodname>dba_open</methodname>
       <methodparam><type>string</type><parameter>path</parameter></methodparam>
       <methodparam><type>string</type><parameter>mode</parameter></methodparam>
       <methodparam><type>string</type><parameter>handler</parameter></methodparam>
@@ -40,6 +40,16 @@
      <function>dba_open</function> returns a positive handle or &false;, in
      the case the open is successful or fails, respectively.
     </para>
+    <note>
+     <para>
+      There can only be one writer for one database file. When you use dba on 
+      a webserver and more than one request requires write operations they can
+      only be done one after another. Unfortuanetly some of the external 
+      libraries simply fail or ignore this when trying to open the database for 
+      another write operation. In this case you must use semaphores to guard
+      against. See <link linkend="ref.sysvsem">System V semaphore support</link>.
+     </para>
+    </note>
     <para>
      See also:
      <function>dba_popen</function>