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Extend r-tree operator classes to handle Y-direction tests equivalent
to the existing X-direction tests. An rtree class now includes 4 actual 2-D tests, 4 1-D X-direction tests, and 4 1-D Y-direction tests. This involved adding four new Y-direction test operators for each of box and polygon; I followed the PostGIS project's lead as to the names of these operators. NON BACKWARDS COMPATIBLE CHANGE: the poly_overleft (&<) and poly_overright (&>) operators now have semantics comparable to box_overleft and box_overright. This is necessary to make r-tree indexes work correctly on polygons. Also, I changed circle_left and circle_right to agree with box_left and box_right --- formerly they allowed the boundaries to touch. This isn't actually essential given the lack of any r-tree opclass for circles, but it seems best to sync all the definitions while we are at it.
This commit is contained in:
Tom Lane
@ -1,5 +1,5 @@
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<!--
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$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.258 2005/06/15 06:29:25 neilc Exp $
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$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.259 2005/06/24 20:53:29 tgl Exp $
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PostgreSQL documentation
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-->
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@ -5854,6 +5854,17 @@ SELECT TIMESTAMP 'now'; -- incorrect for use with DEFAULT
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linkend="functions-geometry-conv-table">.
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</para>
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<caution>
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<para>
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Note that the <quote>same as</> operator, <literal>~=</>, represents
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the usual notion of equality for the <type>point</type>,
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<type>box</type>, <type>polygon</type>, and <type>circle</type> types.
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Some of these types also have an <literal>=</> operator, but it compares
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for equal <emphasis>areas</> only. The other scalar comparison operators
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(<literal><=</> and so on) likewise compare areas for these types.
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</para>
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</caution>
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<table id="functions-geometry-op-table">
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<title>Geometric Operators</title>
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<tgroup cols="3">
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@ -5920,6 +5931,16 @@ SELECT TIMESTAMP 'now'; -- incorrect for use with DEFAULT
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<entry>Overlaps?</entry>
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<entry><literal>box '((0,0),(1,1))' && box '((0,0),(2,2))'</literal></entry>
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</row>
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<row>
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<entry> <literal><<</literal> </entry>
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<entry>Is strictly left of?</entry>
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<entry><literal>circle '((0,0),1)' << circle '((5,0),1)'</literal></entry>
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</row>
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<row>
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<entry> <literal>>></literal> </entry>
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<entry>Is strictly right of?</entry>
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<entry><literal>circle '((5,0),1)' >> circle '((0,0),1)'</literal></entry>
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</row>
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<row>
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<entry> <literal>&<</literal> </entry>
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<entry>Does not extend to the right of?</entry>
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@ -5931,23 +5952,33 @@ SELECT TIMESTAMP 'now'; -- incorrect for use with DEFAULT
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<entry><literal>box '((0,0),(3,3))' &> box '((0,0),(2,2))'</literal></entry>
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</row>
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<row>
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<entry> <literal><<</literal> </entry>
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<entry>Is left of?</entry>
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<entry><literal>circle '((0,0),1)' << circle '((5,0),1)'</literal></entry>
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<entry> <literal><<|</literal> </entry>
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<entry>Is strictly below?</entry>
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<entry><literal>box '((0,0),(3,3))' <<| box '((3,4),(5,5))'</literal></entry>
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</row>
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<row>
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<entry> <literal>>></literal> </entry>
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<entry>Is right of?</entry>
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<entry><literal>circle '((5,0),1)' >> circle '((0,0),1)'</literal></entry>
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<entry> <literal>|>></literal> </entry>
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<entry>Is strictly above?</entry>
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<entry><literal>box '((3,4),(5,5))' |>> box '((0,0),(3,3))'</literal></entry>
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</row>
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<row>
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<entry> <literal>&<|</literal> </entry>
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<entry>Does not extend above?</entry>
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<entry><literal>box '((0,0),(1,1))' &<| box '((0,0),(2,2))'</literal></entry>
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</row>
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<row>
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<entry> <literal>|&></literal> </entry>
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<entry>Does not extend below?</entry>
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<entry><literal>box '((0,0),(3,3))' |&> box '((0,0),(2,2))'</literal></entry>
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</row>
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<row>
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<entry> <literal><^</literal> </entry>
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<entry>Is below?</entry>
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<entry>Is below (allows touching)?</entry>
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<entry><literal>circle '((0,0),1)' <^ circle '((0,5),1)'</literal></entry>
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</row>
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<row>
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<entry> <literal>>^</literal> </entry>
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<entry>Is above?</entry>
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<entry>Is above (allows touching)?</entry>
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<entry><literal>circle '((0,5),1)' >^ circle '((0,0),1)'</literal></entry>
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</row>
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<row>
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@ -1,4 +1,4 @@
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<!-- $PostgreSQL: pgsql/doc/src/sgml/indices.sgml,v 1.50 2005/01/22 22:56:36 momjian Exp $ -->
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<!-- $PostgreSQL: pgsql/doc/src/sgml/indices.sgml,v 1.51 2005/06/24 20:53:30 tgl Exp $ -->
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<chapter id="indexes">
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<title id="indexes-title">Indexes</title>
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@ -177,6 +177,11 @@ CREATE INDEX <replaceable>name</replaceable> ON <replaceable>table</replaceable>
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<member><literal>&<</literal></member>
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<member><literal>&></literal></member>
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<member><literal>>></literal></member>
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<member><literal><<|</literal></member>
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<member><literal>&<|</literal></member>
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<member><literal>|&></literal></member>
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<member><literal>|>></literal></member>
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<member><literal>~</literal></member>
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<member><literal>@</literal></member>
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<member><literal>~=</literal></member>
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<member><literal>&&</literal></member>
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@ -1,5 +1,5 @@
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<!--
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$PostgreSQL: pgsql/doc/src/sgml/xindex.sgml,v 1.39 2005/02/13 03:04:15 tgl Exp $
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$PostgreSQL: pgsql/doc/src/sgml/xindex.sgml,v 1.40 2005/06/24 20:53:30 tgl Exp $
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-->
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<sect1 id="xindex">
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@ -169,8 +169,12 @@ $PostgreSQL: pgsql/doc/src/sgml/xindex.sgml,v 1.39 2005/02/13 03:04:15 tgl Exp $
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</table>
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<para>
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R-tree indexes express rectangle-containment relationships.
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They use eight strategies, shown in <xref linkend="xindex-rtree-strat-table">.
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R-tree indexes express relationships in two-dimensional space.
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They use twelve strategies, shown in
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<xref linkend="xindex-rtree-strat-table">. Four of these are true
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two-dimensional tests (overlaps, same, contains, contained by);
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four of them consider only the X direction; and the other four
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provide the same tests in the Y direction.
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</para>
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<table tocentry="1" id="xindex-rtree-strat-table">
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@ -184,23 +188,23 @@ $PostgreSQL: pgsql/doc/src/sgml/xindex.sgml,v 1.39 2005/02/13 03:04:15 tgl Exp $
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</thead>
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<tbody>
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<row>
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<entry>left of</entry>
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<entry>strictly left of</entry>
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<entry>1</entry>
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</row>
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<row>
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<entry>left of or overlapping</entry>
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<entry>does not extend to right of</entry>
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<entry>2</entry>
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</row>
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<row>
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<entry>overlapping</entry>
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<entry>overlaps</entry>
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<entry>3</entry>
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</row>
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<row>
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<entry>right of or overlapping</entry>
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<entry>does not extend to left of</entry>
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<entry>4</entry>
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</row>
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<row>
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<entry>right of</entry>
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<entry>strictly right of</entry>
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<entry>5</entry>
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</row>
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<row>
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@ -215,6 +219,22 @@ $PostgreSQL: pgsql/doc/src/sgml/xindex.sgml,v 1.39 2005/02/13 03:04:15 tgl Exp $
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<entry>contained by</entry>
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<entry>8</entry>
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</row>
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<row>
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<entry>does not extend above</entry>
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<entry>9</entry>
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</row>
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<row>
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<entry>strictly below</entry>
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<entry>10</entry>
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</row>
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<row>
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<entry>strictly above</entry>
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<entry>11</entry>
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</row>
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<row>
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<entry>does not extend below</entry>
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<entry>12</entry>
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</row>
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</tbody>
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</tgroup>
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</table>
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@ -398,7 +418,7 @@ $PostgreSQL: pgsql/doc/src/sgml/xindex.sgml,v 1.39 2005/02/13 03:04:15 tgl Exp $
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<para>
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Unlike strategy operators, support functions return whichever data
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type the particular index method expects, for example in the case
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type the particular index method expects; for example in the case
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of the comparison function for B-trees, a signed integer.
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</para>
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</sect2>
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