Added support for specification of approximative limits for whole query.

This is specified as attribute type 12. Semantics is the same as
estimatehits in zebra.cfg.

diff --git a/NEWS b/NEWS
index 0de54db..e7c16ba 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,7 @@
+Added support for specification of approximative limits for whole query.
+This is specified as attribute type 12. Semantics is the same as
+estimatehits in zebra.cfg.
+
 --- 2.0.6 2006/11/28
 
 Fixed bug #736: Updates gets slower.

diff --git a/doc/administration.xml b/doc/administration.xml
index 8905d11..ce2e903 100644 (file)
--- a/doc/administration.xml
+++ b/doc/administration.xml
@@ -1,5 +1,5 @@
 <chapter id="administration">
- <!-- $Id: administration.xml,v 1.46 2006-10-11 12:23:24 adam Exp $ -->
+ <!-- $Id: administration.xml,v 1.47 2006-11-30 10:33:19 adam Exp $ -->
  <title>Administrating Zebra</title>
  <!-- ### It's a bit daft that this chapter (which describes half of
           the configuration-file formats) is separated from
@@ -325,7 +325,7 @@
        <para>
        Approximate hit counts can also be triggered by a particular
        attribute in a query.
-       Refer to <xref linkend="querymodel-zebra-attr-approx"/>.
+       Refer to <xref linkend="querymodel-zebra-global-attr-limit"/>.
        </para>
       </listitem>
      </varlistentry>

diff --git a/doc/querymodel.xml b/doc/querymodel.xml
index 6c12214..3a3f781 100644 (file)
--- a/doc/querymodel.xml
+++ b/doc/querymodel.xml
@@ -1,5 +1,5 @@
  <chapter id="querymodel">
-  <!-- $Id: querymodel.xml,v 1.26 2006-09-22 12:34:45 adam Exp $ -->
+  <!-- $Id: querymodel.xml,v 1.27 2006-11-30 10:33:19 adam Exp $ -->
   <title>Query Model</title>
   
   <section id="querymodel-overview">
@@ -205,7 +205,7 @@
          <entry><literal>bib-1</literal></entry>
          <entry>Standard PQF query language attribute set which defines the
           semantics of Z39.50 searching. In addition, all of the
-          non-use attributes (types 2-11) define the hard-wired 
+          non-use attributes (types 2-12) define the hard-wired 
           Zebra internal query
           processing.</entry>
          <entry>default</entry>
@@ -348,7 +348,7 @@
      </para>
      <para>
       Atomic (APT) queries are always leaf nodes in the PQF query tree. 
-      UN-supplied non-use attributes types 2-11 are either inherited from
+      UN-supplied non-use attributes types 2-12 are either inherited from
       higher nodes in the query tree, or are set to Zebra's default values.
       See <xref linkend="querymodel-bib1"/> for details. 
      </para>
@@ -1434,7 +1434,7 @@
     model. These extensions are <emphasis>non-standard</emphasis>
     and <emphasis>non-portable</emphasis>: most functional extensions
     are modeled over the <literal>bib-1</literal> attribute set,
-    defining type 7-9 attributes.
+    defining type 7 and higher values.
     There are also the special 
     <literal>string</literal> type index names for the
     <literal>idxpath</literal> attribute set.  
@@ -1514,17 +1514,23 @@
        <entry>1.1</entry>
        </row>
        <row>
-       <entry>Approx Limit</entry>
-       <entry>11</entry>
+       <entry>Term Reference</entry>
+       <entry>10</entry>
        <entry>search</entry>
        <entry>1.4</entry>
        </row>
        <row>
-       <entry>Term Reference</entry>
-       <entry>10</entry>
+       <entry>Local Approx Limit</entry>
+       <entry>11</entry>
        <entry>search</entry>
        <entry>1.4</entry>
        </row>
+       <row>
+       <entry>Global Approx Limit</entry>
+       <entry>12</entry>
+       <entry>search</entry>
+       <entry>2.0.8</entry>
+       </row>
       </tbody>
      </tgroup>
     </table>      
@@ -1622,12 +1628,37 @@
        Z> find @attr 2=102 @or @attr 9=30 @attr 1=4 utah @attr 9=20 utah
       </screen>
      </para>
-     </section>
+    </section>
+
+    <section id="querymodel-zebra-attr-termref">
+     <title>Zebra Extension Term Reference Attribute (type 10)</title>
+     <para>
+      Zebra supports the searchResult-1 facility. 
+      If the Term Reference Attribute (type 10) is
+      given, that specifies a subqueryId value returned as part of the
+      search result. It is a way for a client to name an APT part of a
+      query. 
+     </para>
+     <!--
+     <para>
+     <screen>
+    </screen>
+    </para>
+     -->
+     <warning>
+      <para>
+       Experimental. Do not use in production code.
+       </para>
+     </warning>
+     
+    </section>
+   
+   
      
-    <section id="querymodel-zebra-attr-limit">
-     <title>Zebra Extension Approximative Limit Attribute (type 11)</title>
+    <section id="querymodel-zebra-local-attr-limit">
+     <title>Local Approximative Limit Attribute (type 11)</title>
      <para>
-      Zebra  computes - unless otherwise configured -
+      Zebra computes - unless otherwise configured -
       the exact hit count for every APT
       (leaf) in the query tree. These hit counts are returned as part of
       the searchResult-1 facility in the binary encoded Z39.50 search
@@ -1663,45 +1694,36 @@
       <para>
        Do not use approximative hit count limits
        in conjunction with relevance ranking, as re-sorting of the
-       result set obviosly only works when the entire result set has
+       result set only works when the entire result set has
        been processed. 
       </para>
      </warning>
-     <warning>
-      <para>
-       This facility clashes with rank weight, because there all
-       documents in the hit lists need to be examined for scoring and
-       re-sorting.
-       It is an experimental
-       extension. Do not use in production code.
-      </para>
-     </warning>
     </section>
 
-    <section id="querymodel-zebra-attr-termref">
-     <title>Zebra Extension Term Reference Attribute (type 10)</title>
+    <section id="querymodel-zebra-global-attr-limit">
+     <title>Global Approximative Limit Attribute (type 12)</title>
      <para>
-      Zebra supports the searchResult-1 facility. 
-      If the Term Reference Attribute (type 10) is
-      given, that specifies a subqueryId value returned as part of the
-      search result. It is a way for a client to name an APT part of a
-      query. 
+      By default Zebra computes precise hit counts for a query as
+      a whole. Setting attribute 12 makes it perform approximative
+      hit counts instead. It has the same semantics as 
+      <literal>estimatehits</literal> for the <xref linkend="zebra-cfg"/>.
      </para>
-     <!--
      <para>
-     <screen>
-    </screen>
-    </para>
-     -->
+      The attribute (12) can occur anywhere in the query tree.
+      Unlike regular attributes it does not relate to the leaf (APT)
+      - but to the whole query.
+     </para>
      <warning>
       <para>
-       Experimental. Do not use in production code.
-       </para>
+       Do not use approximative hit count limits
+       in conjunction with relevance ranking, as re-sorting of the
+       result set only works when the entire result set has
+       been processed. 
+      </para>
      </warning>
-     
     </section>
+
    </section>
-    
 
    <section id="querymodel-zebra-attr-scan">
     <title>Zebra specific Scan Extensions to all Attribute Sets</title>

diff --git a/index/index.h b/index/index.h
index c7993fa..dcb408d 100644 (file)
--- a/index/index.h
+++ b/index/index.h
@@ -1,4 +1,4 @@
-/* $Id: index.h,v 1.184 2006-11-25 09:15:19 adam Exp $
+/* $Id: index.h,v 1.185 2006-11-30 10:33:19 adam Exp $
    Copyright (C) 1995-2006
    Index Data ApS
 
@@ -261,6 +261,9 @@ ZEBRA_RES rpn_search_top(ZebraHandle zh, Z_RPNStructure *zs,
                         int num_bases, char **basenames,
                         RSET *result_set);
 
+ZEBRA_RES rpn_get_top_approx_limit(ZebraHandle zh, Z_RPNStructure *zs,
+                                   zint *approx_limit);
+
 ZEBRA_RES rpn_scan(ZebraHandle zh, ODR stream, Z_AttributesPlusTerm *zapt,
                    oid_value attributeset,
                    int num_bases, char **basenames,

diff --git a/index/rpnsearch.c b/index/rpnsearch.c
index 3057580..9529573 100644 (file)
--- a/index/rpnsearch.c
+++ b/index/rpnsearch.c
@@ -1,4 +1,4 @@
-/* $Id: rpnsearch.c,v 1.2 2006-10-12 12:28:42 adam Exp $
+/* $Id: rpnsearch.c,v 1.3 2006-11-30 10:33:19 adam Exp $
    Copyright (C) 1995-2006
    Index Data ApS
 
@@ -2318,6 +2318,37 @@ static ZEBRA_RES rpn_search_structure(ZebraHandle zh, Z_RPNStructure *zs,
                                      Z_Operator *parent_op,
                                      struct rset_key_control *kc);
 
+ZEBRA_RES rpn_get_top_approx_limit(ZebraHandle zh, Z_RPNStructure *zs,
+                                   zint *approx_limit)
+{
+    ZEBRA_RES res = ZEBRA_OK;
+    if (zs->which == Z_RPNStructure_complex)
+    {
+        if (res == ZEBRA_OK)
+            res = rpn_get_top_approx_limit(zh, zs->u.complex->s1,
+                                           approx_limit);
+        if (res == ZEBRA_OK)
+            res = rpn_get_top_approx_limit(zh, zs->u.complex->s2,
+                                           approx_limit);
+    }
+    else if (zs->which == Z_RPNStructure_simple)
+    {
+        if (zs->u.simple->which == Z_Operand_APT)
+        {
+            Z_AttributesPlusTerm *zapt = zs->u.simple->u.attributesPlusTerm;
+            AttrType global_hits_limit_attr;
+            int l;
+            
+            attr_init_APT(&global_hits_limit_attr, zapt, 12);
+            
+            l = attr_find(&global_hits_limit_attr, NULL);
+            if (l != -1)
+                *approx_limit = l;
+        }
+    }
+    return res;
+}
+
 ZEBRA_RES rpn_search_top(ZebraHandle zh, Z_RPNStructure *zs,
                         oid_value attributeSet, 
                         NMEM stream, NMEM rset_nmem,

diff --git a/index/zsets.c b/index/zsets.c
index 643ba2c..5c02dd4 100644 (file)
--- a/index/zsets.c
+++ b/index/zsets.c
@@ -1,4 +1,4 @@
-/* $Id: zsets.c,v 1.112 2006-10-29 17:20:01 adam Exp $
+/* $Id: zsets.c,v 1.113 2006-11-30 10:33:19 adam Exp $
    Copyright (C) 1995-2006
    Index Data ApS
 
@@ -94,6 +94,7 @@ static void loglevels(void)
     log_level_set = 1;
 }
 
+
 ZEBRA_RES resultSetSearch(ZebraHandle zh, NMEM nmem, NMEM rset_nmem,
                          Z_RPNQuery *rpn, ZebraSet sset)
 {
@@ -115,6 +116,9 @@ ZEBRA_RES resultSetSearch(ZebraHandle zh, NMEM nmem, NMEM rset_nmem,
         sort_sequence->specs[i] = 0;
     
     attrset = oid_getentbyoid (rpn->attributeSetId);
+
+    rpn_get_top_approx_limit(zh, rpn->RPNStructure, &sset->approx_limit);
+
     res = rpn_search_top(zh, rpn->RPNStructure, attrset->value,
                         nmem, rset_nmem,
                         sort_sequence,