<div dir="ltr">Hi Walter, hi all,<br><div class="gmail_extra">from the grammar point of view it seems correct because the</div><div class="gmail_extra">[ &lt;schema_name&gt; &lt;period&gt; ]<br></div><div class="gmail_extra">in the &lt;table_name&gt; rule is optional and there are no other </div><div class="gmail_extra">grammar rules that will suffer from it, the only other places </div><div class="gmail_extra">the &lt;qualifier&gt; is used being</div><div class="gmail_extra"><br></div><div class="gmail_extra"><div class="gmail_extra">&lt;select_sublist&gt; ::= &lt;derived_column&gt; | &lt;qualifier&gt; &lt;period&gt; &lt;asterisk&gt;</div><div class="gmail_extra">&lt;column_reference&gt; ::= [ &lt;qualifier&gt; &lt;period&gt; ] &lt;column_name&gt;</div></div><div class="gmail_extra"><br></div><div class="gmail_extra">My thought, however, is that table names and correlation names are</div><div class="gmail_extra">different concepts in SQL, so my choice would be not to simplify that rule, </div><div class="gmail_extra">simplification that sounds to me like implicitly meaning that a correlation </div><div class="gmail_extra">name is the same as an unqualified table name (when used as a qualifier).</div><div class="gmail_extra"><br></div><div class="gmail_extra">Cheers,</div><div class="gmail_extra">     Marco</div><div class="gmail_extra"><br><div class="gmail_quote">2015-01-13 22:23 GMT+01:00 Walter Landry <span dir="ltr">&lt;<a href="mailto:wlandry@caltech.edu" target="_blank">wlandry@caltech.edu</a>&gt;</span>:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">Hello Everyone,<br>
<br>
In ADQL, the rules for qualifier, table_name, and correlatio_name are<br>
<br>
  &lt;qualifier&gt; ::= &lt;table_name&gt; | &lt;correlation_name&gt;<br>
  &lt;table_name&gt; ::= [ &lt;schema_name&gt; &lt;period&gt; ] &lt;identifier&gt;<br>
  &lt;correlation_name&gt; ::= &lt;identifier&gt;<br>
<br>
It seems that table_name matches everything that correlation_name<br>
matches.  If so, couldn&#39;t we simplify the grammar by making<br>
<br>
  &lt;qualifier&gt; ::= &lt;table_name&gt;<br>
<br>
This seems to be something that is inherited from SQL 92<br>
<br>
  <a href="http://savage.net.au/SQL/sql-92.bnf.html#qualifier" target="_blank">http://savage.net.au/SQL/sql-92.bnf.html#qualifier</a><br>
<br>
so we probably can not fix it.  I just wanted to make sure I<br>
understand the grammar.<br>
<br>
Thanks,<br>
Walter Landry<br>
</blockquote></div><br></div></div>