Integrated resource owner patch by Alexander Alexeev. This patch makes performance of resource deletion linear of number of used resources, which improves performance for heavily partitioned tables and queries which use large number of resoures

vbwagner · vbwagner · commit 1d9bdd2a5091 · 2016-01-08T16:25:26.000+03:00
diff --git a/doc/src/sgml/release-pro-9.5.sgml b/doc/src/sgml/release-pro-9.5.sgml
@@ -23,6 +23,7 @@
 
     <listitem>
      <para>
+       Scalability improvement for multicore/multeprocessor systems.
      </para>
     </listitem>
 
@@ -91,11 +92,19 @@
     <listitem>
 <!-- Put commit message here -->      
     <para>
-    
-       <!-- to be filled -->
+       Scalability improvements for multicore/multiprocessor systems:  
+    </para>
+    <itemizedlist>
+    <listitem>
+    <para>Resource owner optimisation for complicated queries: now
+    resource lists has constant access time, which improves performance
+    for heavily partitioned tables and queries which use hundreds of
+    tables.
     </para>
     </listitem>
      </itemizedlist>
+    </listitem>
+     </itemizedlist>
 
     </sect4>
 
diff --git a/src/backend/access/hash/hashfunc.c b/src/backend/access/hash/hashfunc.c
@@ -297,6 +297,9 @@ hashvarlena(PG_FUNCTION_ARGS)
  * of 2.  There is no need to do mod a prime (mod is sooo slow!).
  * If you need less than 32 bits, use a bitmask.
  *
+ * This procedure never fails. Its important. Some code notably ResourceOwner
+ * relies on this.
+ *
  * Note: we could easily change this function to return a 64-bit hash value
  * by using the final values of both b and c.  b is perhaps a little less
  * well mixed than c, however.
diff --git a/src/backend/utils/resowner/resowner.c b/src/backend/utils/resowner/resowner.c
