initial import

git-svn-id: http://svn.osgeo.org/postgis/trunk@464 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/utils/README b/utils/README
new file mode 100644 (file)
index 0000000..4d66522
--- /dev/null
+++ b/utils/README
@@ -0,0 +1,2 @@
+test_estimation.pl
+       test selectivity estimator for the && (overlap) operator

diff --git a/utils/test_estimation.pl b/utils/test_estimation.pl
new file mode 100755 (executable)
index 0000000..dca519a
--- /dev/null
+++ b/utils/test_estimation.pl
@@ -0,0 +1,214 @@
+#!/usr/bin/perl 
+
+# $Id$
+
+use Pg;
+
+$VERBOSE = 0;
+
+sub usage
+{
+       local($me) = `basename $0`;
+       chop($me);
+       print STDERR "$me <table> <col> [-v]\n";
+}
+
+if ( ! $ARGV[1] ) {
+       &usage();
+       exit 1;
+}
+
+$SCHEMA = 'public';
+$TABLE = $ARGV[0];
+if ( $TABLE =~ /(.*)\.(.*)/ ) 
+{
+       $SCHEMA = $1;
+       $TABLE = $2;
+}
+$COLUMN = $ARGV[1];
+
+$VERBOSE=1 if $ARGV[2] eq '-v';
+
+#connect
+$conn = Pg::connectdb("");
+if ( $conn->status != PGRES_CONNECTION_OK ) {
+        print STDERR $conn->errorMessage;
+       exit(1);
+}
+
+# Get extent
+
+$query = 'select extent("'.$COLUMN.'"), min(geometrytype("'.$COLUMN.'")) from "'.$SCHEMA.'"."'.$TABLE.'"';
+$res = $conn->exec($query);
+if ( $res->resultStatus != PGRES_TUPLES_OK )  {
+       print STDERR $conn->errorMessage;
+       exit(1);
+}
+$TYPE = $res->getvalue(0, 1);
+$EXTENT = $res->getvalue(0, 0);
+
+# find srid
+$query = 'select srid("'.$COLUMN.'") from "'.$SCHEMA.'"."'.$TABLE.'"';
+$res = $conn->exec($query);
+if ( $res->resultStatus != PGRES_TUPLES_OK )  {
+       print STDERR $conn->errorMessage;
+       exit(1);
+}
+$SRID = $res->getvalue(0, 0);
+
+
+# parse extent
+$EXTENT =~ /^BOX3D\((.*) (.*) (.*),(.*) (.*) (.*)\)$/;
+$ext{xmin} = $1;
+$ext{ymin} = $2;
+$ext{xmax} = $4;
+$ext{ymax} = $5;
+
+# vacuum analyze table
+$query = 'vacuum analyze "'.$SCHEMA.'"."'.$TABLE.'"';
+$res = $conn->exec($query);
+if ( $res->resultStatus != PGRES_COMMAND_OK )  {
+       print STDERR $conn->errorMessage;
+       exit(1);
+}
+
+
+@extents = ( \%ext );
+
+print "Type: $TYPE\n";
+
+$ext = \%ext;
+#print "BPS: $bps (".@extents." cells)\n";
+print "  bps\test\treal\tdelta\tmatch_factor\n";
+print "----------------------------------------------------------\n";
+for ($bps=1; $bps<=32; $bps*=2)
+{
+       split_extent($ext, $bps, \@extents);
+
+
+       $best_match_factor=10000;
+       $worst_match_factor=1;
+       $sum_match_factors=0;
+       $count_match_factors=0;
+       while ( ($cell_ext=pop(@extents)) )
+       {
+               ($est,$real) = test_extent($cell_ext);
+               $delta = $est-$real;
+
+               print "    $bps\t".$est."\t".$real."\t$delta";
+               if ($real)
+               {
+                       $match_factor = $est/$real;
+                       if ( $match_factor && $match_factor < 1 )
+                       {
+                               $match_factor = - (1/$match_factor);
+                       }
+                       $match_factor = int($match_factor*1000)/1000;
+                       print "\t$match_factor";
+                       $count_match_factors++;
+
+                       $abs_match_factor = abs($match_factor);
+                       $sum_match_factors += $abs_match_factor;
+                       if ( $abs_match_factor > $worst_match_factor )
+                       {
+                               $worst_match_factor = $match_factor;
+                       }
+                       if ( $abs_match_factor < $best_match_factor )
+                       {
+                               $best_match_factor = $match_factor;
+                       }
+               }
+               print "\n";
+       }
+       $avg_match_factor = $sum_match_factors/$count_match_factors;
+       $avg_match_factor = int($avg_match_factor*1000)/1000;
+       print "(bps/best/worst/avg):\t".
+               $bps."\t".
+               $best_match_factor."\t".
+               $worst_match_factor."\t".$avg_match_factor."\n";
+}
+
+
+##################################################################
+
+sub print_extent
+{
+       local($ext) = shift;
+       local($s);
+
+       $s = $ext->{'xmin'}." ".$ext->{'ymin'}."  ";
+       $s .= $ext->{'xmax'}." ".$ext->{'ymax'};
+
+       return $s;
+}
+
+sub split_extent
+{
+       local($ext) = shift;
+       local($bps) = shift;
+       local($stack) = shift;
+
+       local($width, $height, $cell_width, $cell_height);
+       local($x,$y);
+
+       $width = $ext->{'xmax'} - $ext->{'xmin'};
+       $height = $ext->{'ymax'} - $ext->{'ymin'};
+       $cell_width = $width / $bps;
+       $cell_height = $height / $bps;
+
+       if ($VERBOSE)
+       {
+               print "cell_w: $cell_width\n";
+               print "cell_h: $cell_height\n";
+       }
+
+       @$stack = ();
+       for ($x=$ext->{'xmin'}; $x<$ext->{'xmax'}; $x += $cell_width)
+       {
+               #print "X: $x\n";
+               for ($y=$ext->{'ymin'}; $y<$ext->{'ymax'}; $y += $cell_height)
+               {
+                       local(%cell);
+                       #print "Y: $y\n";
+                       $cell{'xmin'} = $x;
+                       $cell{'ymin'} = $y;
+                       $cell{'xmax'} = $x+$cell_width;
+                       $cell{'ymax'} = $y+$cell_height;
+                       #print "PUSH\n";
+                       push(@$stack, \%cell);
+               }
+       }
+}
+
+sub test_extent
+{
+       local($ext) = shift;
+
+       # Test whole extent query
+       $query = 'explain analyze select oid from "'.
+               $SCHEMA.'"."'.$TABLE.'" WHERE "'.$COLUMN.'" && '.
+               "'SRID=$SRID;BOX3D(".$ext->{'xmin'}." ".
+               $ext->{'ymin'}.", ".$ext->{'xmax'}." ".
+               $ext->{'ymax'}.")'";
+       $res = $conn->exec($query);
+       if ( $res->resultStatus != PGRES_TUPLES_OK )  {
+               print STDERR $conn->errorMessage;
+               exit(1);
+       }
+       while ( ($row=$res->fetchrow()) )
+       {
+               next unless $row =~ /.* rows=([0-9]+) .* rows=([0-9]+) /;
+               $est = $1;
+               $real = $2;
+               last;
+       }
+
+       return ($est,$real);
+}
+
+# 
+# $Log$
+# Revision 1.1  2004/03/05 11:52:24  strk
+# initial import
+#
+#