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+<p>
+  Exploring an LTPDA repository is most easily achieved using the purpose-built graphical user interface. This
+  interace is accesible either from the LTPDA workbench, or via a toolbar button the workspace browser.
+</p>
+<p>
+  The figure belows shows the query dialog that appears through either interface:
+  <br>
+  <img src="images/querydialog.png" alt="LTPDA Query Builder" border="3">
+  <br>
+</p>
+<p>
+  You can construct a query by use of the drop-down menus and buttons, then execute
+  the query to retreive a table of results, like the one shown below:
+  <br>
+  <img src="images/queryresults.png" alt="LTPDA Query Results" border="3">
+  <br>
+</p>
+<p>
+  If the query dialog is launched from within the LTPDA Workbench, the results table has an
+  additional button which can be used to create constructor blocks on the current pipeline
+  corresponding to the selected records in the results table.
+</p>
+
+
+<!--
+<p>
+  Since an LTPDA repository is just a MySQL database, you can query the database using standard
+  SQL commands via any of the popular MySQL clients. In addition, the LTPDA toolbox provides a 
+  simplified command that can be used to execute simple queries with only basic SQL knowledge.
+</p>
+<p>
+  The command is <tt>utils.mysql.dbquery</tt> and it can be used to perform various queries.
+  It takes the following input arguments:
+  <table border="1" cellpadding="2" width="30%" bgcolor="#DDDDDD">
+    <tr valign="top">
+      <td><tt>conn</tt></td><td>A database connection object</td>
+    </tr>
+    <tr valign="top">
+      <td><tt>tablename</tt></td><td>The name of a table to search</td>
+    </tr>
+    <tr valign="top">
+      <td><tt>query</tt></td><td>The query string written in MySQL SQL syntax</td>
+    </tr>
+  </table>	 
+  <br>
+Examples of usage are:
+
+</p>
+   
+<h2>Searching particular tables</h2>
+ 
+<p> 
+  <div class="fragment"><pre>
+      >> info  = utils.mysql.dbquery(conn, 'select * from objmeta where id>1000 and id<2000');
+      >> info  = utils.mysql.dbquery(conn, 'ao',           'id>1000 and id<2000');
+      >> info  = utils.mysql.dbquery_dbquery(conn, 'objmeta',      'name like "x12"');
+      >> info  = utils.mysql.dbquery(conn, 'users',        'username="aouser"');
+      >> info  = utils.mysql.dbquery(conn, 'collections',  'id=3');
+      >> info  = utils.mysql.dbquery(conn, 'collections',  'obj_ids="1,2"');
+      >> info  = utils.mysql.dbquery(conn, 'transactions', 'user_id=3');
+      >> info  = utils.mysql.dbquery(conn, 'transactions', 'obj_id=56');
+  </pre></div>
+</p>
+ 
+<h2>Retrieving a list of tables</h2>
+ 
+<p> 
+  You can retrieve a list of the tables in a database with the call:
+  <div class="fragment"><pre>
+      >> info  = utils.mysql.dbquery(conn)
+  </pre></div>
+  
+</p>
+
+  
+<h2>High-level queries</h2>
+<p>
+  Various standard queries are envisaged which ask typical questions, such as:
+  "Give me data for a particular signal spanning a particular time-span".  
+</p>
+<p>
+  Formulating this question as an SQL query requires a good knowledge of the SQL
+  syntax used by MySQL. The query has to search across multiple tables in order
+  to gather the IDs of the objects that fulfill the query. For these standard questions,
+  high-level functions will be built which perform the query given some input information. This
+  avoids the user having to formulate complicated SQL statements.
+</p>
+<p>
+  The following high-level queries currently exist in the toolbox:
+<table border="1" cellpadding="2" bgcolor="#DDDDDD">
+  <tr valign="top">
+    <td><tt>ltpda_getAOsInTimeSpan</tt></td><td>Retrieve particular AOs in the given time-span</td>
+  </tr>
+</table>
+</p>
+
+-->