Add BRIN infrastructure for "inclusion" opclasses

This lets BRIN be used with R-Tree-like indexing strategies.

Also provided are operator classes for range types, box and inet/cidr.
The infrastructure provided here should be sufficient to create operator
classes for similar datatypes; for instance, opclasses for PostGIS
geometries should be doable, though we didn't try to implement one.

(A box/point opclass was also submitted, but we ripped it out before
commit because the handling of floating point comparisons in existing
code is inconsistent and would generate corrupt indexes.)

Author: Emre Hasegeli.  Cosmetic changes by me
Review: Andreas Karlsson

Author: alvherre

doc/src/sgml/brin.sgml

@@ -72,7 +72,9 @@
  <para>
   The <firstterm>minmax</>
   operator classes store the minimum and the maximum values appearing
-  in the indexed column within the range.
+  in the indexed column within the range.  The <firstterm>inclusion</>
+  operator classes store a value which includes the values in the indexed
+  column within the range.
  </para>
 
  <table id="brin-builtin-opclasses-table">
@@ -251,6 +253,18 @@
       <literal>&gt;</literal>
      </entry>
     </row>
+    <row>
+     <entry><literal>inet_inclusion_ops</literal></entry>
+     <entry><type>inet</type></entry>
+     <entry>
+      <literal>&amp;&amp;</>
+      <literal>&gt;&gt;</>
+      <literal>&gt;&gt;=</>
+      <literal>&lt;&lt;</literal>
+      <literal>&lt;&lt;=</literal>
+      <literal>=</literal>
+     </entry>
+    </row>
     <row>
      <entry><literal>bpchar_minmax_ops</literal></entry>
      <entry><type>character</type></entry>
@@ -372,6 +386,25 @@
       <literal>&gt;</literal>
      </entry>
     </row>
+    <row>
+     <entry><literal>range_inclusion_ops</></entry>
+     <entry><type>any range type</type></entry>
+     <entry>
+      <literal>&amp;&amp;</>
+      <literal>&amp;&gt;</>
+      <literal>&amp;&lt;</>
+      <literal>&gt;&gt;</>
+      <literal>&lt;&lt;</>
+      <literal>&lt;@</>
+      <literal>=</>
+      <literal>@&gt;</>
+      <literal>&lt;</literal>
+      <literal>&lt;=</literal>
+      <literal>=</literal>
+      <literal>&gt;=</literal>
+      <literal>&gt;</literal>
+     </entry>
+    </row>
     <row>
      <entry><literal>pg_lsn_minmax_ops</literal></entry>
      <entry><type>pg_lsn</type></entry>
@@ -383,6 +416,24 @@
       <literal>&gt;</literal>
      </entry>
     </row>
+    <row>
+     <entry><literal>box_inclusion_ops</></entry>
+     <entry><type>box</type></entry>
+     <entry>
+      <literal>&amp;&amp;</>
+      <literal>&amp;&gt;</>
+      <literal>&amp;&lt;</>
+      <literal>&gt;&gt;</>
+      <literal>&lt;&lt;</>
+      <literal>&lt;@</>
+      <literal>~=</>
+      <literal>@&gt;</>
+      <literal>&amp;&gt;|</>
+      <literal>|&amp;&lt;</>
+      <literal>&gt;&gt;|</>
+      <literal>|&lt;&lt;</literal>
+     </entry>
+    </row>
    </tbody>
   </tgroup>
  </table>

src/backend/access/brin/Makefile

@@ -13,6 +13,6 @@ top_builddir = ../../../..
 include $(top_builddir)/src/Makefile.global
 
 OBJS = brin.o brin_pageops.o brin_revmap.o brin_tuple.o brin_xlog.o \
-	   brin_minmax.o
+       brin_minmax.o brin_inclusion.o
 
 include $(top_srcdir)/src/backend/common.mk

src/backend/access/brin/brin.c

@@ -105,11 +105,6 @@ brininsert(PG_FUNCTION_ARGS)
 		BrinMemTuple *dtup;
 		BlockNumber heapBlk;
 		int			keyno;
-#ifdef USE_ASSERT_CHECKING
-		BrinTuple  *tmptup;
-		BrinMemTuple *tmpdtup;
-		Size 		tmpsiz;
-#endif
 
 		CHECK_FOR_INTERRUPTS();
 
@@ -137,45 +132,6 @@ brininsert(PG_FUNCTION_ARGS)
 
 		dtup = brin_deform_tuple(bdesc, brtup);
 
-#ifdef USE_ASSERT_CHECKING
-		{
-			/*
-			 * When assertions are enabled, we use this as an opportunity to
-			 * test the "union" method, which would otherwise be used very
-			 * rarely: first create a placeholder tuple, and addValue the
-			 * value we just got into it.  Then union the existing index tuple
-			 * with the updated placeholder tuple.  The tuple resulting from
-			 * that union should be identical to the one resulting from the
-			 * regular operation (straight addValue) below.
-			 *
-			 * Here we create the tuple to compare with; the actual comparison
-			 * is below.
-			 */
-			tmptup = brin_form_placeholder_tuple(bdesc, heapBlk, &tmpsiz);
-			tmpdtup = brin_deform_tuple(bdesc, tmptup);
-			for (keyno = 0; keyno < bdesc->bd_tupdesc->natts; keyno++)
-			{
-				BrinValues *bval;
-				FmgrInfo   *addValue;
-
-				bval = &tmpdtup->bt_columns[keyno];
-				addValue = index_getprocinfo(idxRel, keyno + 1,
-											 BRIN_PROCNUM_ADDVALUE);
-				FunctionCall4Coll(addValue,
-								  idxRel->rd_indcollation[keyno],
-								  PointerGetDatum(bdesc),
-								  PointerGetDatum(bval),
-								  values[keyno],
-								  nulls[keyno]);
-			}
-
-			union_tuples(bdesc, tmpdtup, brtup);
-
-			tmpdtup->bt_placeholder = dtup->bt_placeholder;
-			tmptup = brin_form_tuple(bdesc, heapBlk, tmpdtup, &tmpsiz);
-		}
-#endif
-
 		/*
 		 * Compare the key values of the new tuple to the stored index values;
 		 * our deformed tuple will get updated if the new tuple doesn't fit
@@ -202,20 +158,6 @@ brininsert(PG_FUNCTION_ARGS)
 			need_insert |= DatumGetBool(result);
 		}
 
-#ifdef USE_ASSERT_CHECKING
-		{
-			/*
-			 * Now we can compare the tuple produced by the union function
-			 * with the one from plain addValue.
-			 */
-			BrinTuple  *cmptup;
-			Size		cmpsz;
-
-			cmptup = brin_form_tuple(bdesc, heapBlk, dtup, &cmpsz);
-			Assert(brin_tuples_equal(tmptup, tmpsiz, cmptup, cmpsz));
-		}
-#endif
-
 		if (!need_insert)
 		{
 			/*
@@ -323,8 +265,6 @@ brinbeginscan(PG_FUNCTION_ARGS)
  * If a TID from the revmap is read as InvalidTID, we know that range is
  * unsummarized.  Pages in those ranges need to be returned regardless of scan
  * keys.
- *
- * XXX see _bt_first on what to do about sk_subtype.
  */
 Datum
 bringetbitmap(PG_FUNCTION_ARGS)
@@ -340,7 +280,6 @@ bringetbitmap(PG_FUNCTION_ARGS)
 	BlockNumber nblocks;
 	BlockNumber heapBlk;
 	int			totalpages = 0;
-	int			keyno;
 	FmgrInfo   *consistentFn;
 	MemoryContext oldcxt;
 	MemoryContext perRangeCxt;
@@ -359,18 +298,11 @@ bringetbitmap(PG_FUNCTION_ARGS)
 	heap_close(heapRel, AccessShareLock);
 
 	/*
-	 * Obtain consistent functions for all indexed column.  Maybe it'd be
-	 * possible to do this lazily only the first time we see a scan key that
-	 * involves each particular attribute.
+	 * Make room for the consistent support procedures of indexed columns.  We
+	 * don't look them up here; we do that lazily the first time we see a scan
+	 * key reference each of them.  We rely on zeroing fn_oid to InvalidOid.
 	 */
-	consistentFn = palloc(sizeof(FmgrInfo) * bdesc->bd_tupdesc->natts);
-	for (keyno = 0; keyno < bdesc->bd_tupdesc->natts; keyno++)
-	{
-		FmgrInfo   *tmp;
-
-		tmp = index_getprocinfo(idxRel, keyno + 1, BRIN_PROCNUM_CONSISTENT);
-		fmgr_info_copy(&consistentFn[keyno], tmp, CurrentMemoryContext);
-	}
+	consistentFn = palloc0(sizeof(FmgrInfo) * bdesc->bd_tupdesc->natts);
 
 	/*
 	 * Setup and use a per-range memory context, which is reset every time we
@@ -418,7 +350,6 @@ bringetbitmap(PG_FUNCTION_ARGS)
 		else
 		{
 			BrinMemTuple *dtup;
-			int			keyno;
 
 			dtup = brin_deform_tuple(bdesc, tup);
 			if (dtup->bt_placeholder)
@@ -431,6 +362,8 @@ bringetbitmap(PG_FUNCTION_ARGS)
 			}
 			else
 			{
+				int			keyno;
+
 				/*
 				 * Compare scan keys with summary values stored for the range.
 				 * If scan keys are matched, the page range must be added to
@@ -456,6 +389,17 @@ bringetbitmap(PG_FUNCTION_ARGS)
 						   (key->sk_collation ==
 					   bdesc->bd_tupdesc->attrs[keyattno - 1]->attcollation));
 
+					/* First time this column? look up consistent function */
+					if (consistentFn[keyattno - 1].fn_oid == InvalidOid)
+					{
+						FmgrInfo   *tmp;
+
+						tmp = index_getprocinfo(idxRel, keyattno,
+												BRIN_PROCNUM_CONSISTENT);
+						fmgr_info_copy(&consistentFn[keyattno - 1], tmp,
+									   CurrentMemoryContext);
+					}
+
 					/*
 					 * Check whether the scan key is consistent with the page
 					 * range values; if so, have the pages in the range added