<p><b> Selections </b> select all titles whose at least one author is "Alain Frisch" or "Veronique Benzaken"</p>
<p>
But the <code>select_from_where</code> expressions are likely to be used for
more complex queries such as the one that selects all titles whose at least one
author is "Alain Frisch" or "Veronique Benzaken"
</p>
<sample><![CDATA[
let sel = select y
from x in [bib]/<paper>_ ,
...
...
@@ -244,12 +257,13 @@ Ok.
<p>Note that the corresponding semantics, as in SQL, is a multiset one.
Thus duplicates are not eliminated. To discard them, one has to use the <code>distinct_values</code> operator.
</p>
</section>
<sectiontitle="A pure pattern example">
<p>
<b> A pure pattern example </b></p>
<p>
This example computes the same result as the previous query except that duplicates are eliminated. It is written in a pure pattern form (i.e., without any XPath-like projections)
This example computes the same result as the previous query except that
duplicates are eliminated. It is written in a pure pattern form (i.e., without
any XPath-like projections)
</p>
<sample><![CDATA[
...
...
@@ -275,17 +289,19 @@ Ok.
]]>
</sample>
<p>
This pure pattern form of the query yields (in general) better performance than the same one written in an XQuery-like programming style. However, the query optimiser automatically translates the latter into a pure pattern one
This pure pattern form of the query yields (in general) better performance than
the same one written in an XQuery-like programming style. However, the query
optimiser automatically translates the latter into a pure pattern one
