From 58fe455621f57ed3d19c4afdee6b46905c9b048a Mon Sep 17 00:00:00 2001
From: Tpt <thomaspt@hotmail.fr>
Date: Fri, 25 Oct 2019 12:06:35 +0200
Subject: [PATCH] Tweaks the join reordering algorithm to prefer using bound
 variables

---
 bench/bsbm.explore.svg         | 300 ++++++++++++++++-----------------
 lib/src/sparql/plan_builder.rs |  16 +-
 2 files changed, 161 insertions(+), 155 deletions(-)

diff --git a/bench/bsbm.explore.svg b/bench/bsbm.explore.svg
index a46d17a7..4bef93e5 100644
--- a/bench/bsbm.explore.svg
+++ b/bench/bsbm.explore.svg
@@ -27,354 +27,354 @@ z
 " style="fill:#ffffff;"/>
    </g>
    <g id="patch_3">
-    <path clip-path="url(#p67969da4ac)" d="M 73.832727 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 73.832727 307.584 
 L 79.335347 307.584 
-L 79.335347 251.012211 
-L 73.832727 251.012211 
+L 79.335347 251.315159 
+L 73.832727 251.315159 
 z
 " style="fill:#1f77b4;"/>
    </g>
    <g id="patch_4">
-    <path clip-path="url(#p67969da4ac)" d="M 101.345824 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 101.345824 307.584 
 L 106.848444 307.584 
-L 106.848444 239.522917 
-L 101.345824 239.522917 
+L 106.848444 239.887391 
+L 101.345824 239.887391 
 z
 " style="fill:#1f77b4;"/>
    </g>
    <g id="patch_5">
-    <path clip-path="url(#p67969da4ac)" d="M 128.858921 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 128.858921 307.584 
 L 134.361541 307.584 
-L 134.361541 238.467915 
-L 128.858921 238.467915 
+L 134.361541 238.838039 
+L 128.858921 238.838039 
 z
 " style="fill:#1f77b4;"/>
    </g>
    <g id="patch_6">
-    <path clip-path="url(#p67969da4ac)" d="M 156.372018 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 156.372018 307.584 
 L 161.874638 307.584 
-L 161.874638 230.035973 
-L 156.372018 230.035973 
+L 161.874638 230.451251 
+L 156.372018 230.451251 
 z
 " style="fill:#1f77b4;"/>
    </g>
    <g id="patch_7">
-    <path clip-path="url(#p67969da4ac)" d="M 183.885116 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 183.885116 307.584 
 L 189.387735 307.584 
-L 189.387735 131.686644 
-L 183.885116 131.686644 
+L 189.387735 132.628593 
+L 183.885116 132.628593 
 z
 " style="fill:#1f77b4;"/>
    </g>
    <g id="patch_8">
-    <path clip-path="url(#p67969da4ac)" d="M 238.91131 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 238.91131 307.584 
 L 244.413929 307.584 
-L 244.413929 253.060314 
-L 238.91131 253.060314 
+L 244.413929 253.352294 
+L 238.91131 253.352294 
 z
 " style="fill:#1f77b4;"/>
    </g>
    <g id="patch_9">
-    <path clip-path="url(#p67969da4ac)" d="M 266.424407 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 266.424407 307.584 
 L 271.927026 307.584 
-L 271.927026 241.094654 
-L 266.424407 241.094654 
+L 271.927026 241.450712 
+L 266.424407 241.450712 
 z
 " style="fill:#1f77b4;"/>
    </g>
    <g id="patch_10">
-    <path clip-path="url(#p67969da4ac)" d="M 293.937504 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 293.937504 307.584 
 L 299.440123 307.584 
-L 299.440123 267.294767 
-L 293.937504 267.294767 
+L 299.440123 267.51052 
+L 293.937504 267.51052 
 z
 " style="fill:#1f77b4;"/>
    </g>
    <g id="patch_11">
-    <path clip-path="url(#p67969da4ac)" d="M 321.450601 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 321.450601 307.584 
 L 326.95322 307.584 
-L 326.95322 236.592057 
-L 321.450601 236.592057 
+L 326.95322 236.972226 
+L 321.450601 236.972226 
 z
 " style="fill:#1f77b4;"/>
    </g>
    <g id="patch_12">
-    <path clip-path="url(#p67969da4ac)" d="M 348.963698 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 348.963698 307.584 
 L 354.466317 307.584 
-L 354.466317 268.557001 
-L 348.963698 268.557001 
+L 354.466317 268.765995 
+L 348.963698 268.765995 
 z
 " style="fill:#1f77b4;"/>
    </g>
    <g id="patch_13">
-    <path clip-path="url(#p67969da4ac)" d="M 376.476795 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 376.476795 307.584 
 L 381.979414 307.584 
-L 381.979414 254.847358 
-L 376.476795 254.847358 
+L 381.979414 255.129769 
+L 376.476795 255.129769 
 z
 " style="fill:#1f77b4;"/>
    </g>
    <g id="patch_14">
-    <path clip-path="url(#p67969da4ac)" d="M 79.335347 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 79.335347 307.584 
 L 84.837966 307.584 
-L 84.837966 304.295193 
-L 79.335347 304.295193 
+L 84.837966 304.312805 
+L 79.335347 304.312805 
 z
 " style="fill:#ff7f0e;"/>
    </g>
    <g id="patch_15">
-    <path clip-path="url(#p67969da4ac)" d="M 106.848444 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 106.848444 307.584 
 L 112.351063 307.584 
-L 112.351063 300.861054 
-L 106.848444 300.861054 
+L 112.351063 300.897056 
+L 106.848444 300.897056 
 z
 " style="fill:#ff7f0e;"/>
    </g>
    <g id="patch_16">
-    <path clip-path="url(#p67969da4ac)" d="M 134.361541 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 134.361541 307.584 
 L 139.86416 307.584 
-L 139.86416 303.614286 
-L 134.361541 303.614286 
+L 139.86416 303.635544 
+L 134.361541 303.635544 
 z
 " style="fill:#ff7f0e;"/>
    </g>
    <g id="patch_17">
-    <path clip-path="url(#p67969da4ac)" d="M 161.874638 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 161.874638 307.584 
 L 167.377257 307.584 
-L 167.377257 303.25903 
-L 161.874638 303.25903 
+L 167.377257 303.282191 
+L 161.874638 303.282191 
 z
 " style="fill:#ff7f0e;"/>
    </g>
    <g id="patch_18">
-    <path clip-path="url(#p67969da4ac)" d="M 189.387735 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 189.387735 307.584 
 L 194.890354 307.584 
-L 194.890354 273.958504 
-L 189.387735 273.958504 
+L 194.890354 274.138572 
+L 189.387735 274.138572 
 z
 " style="fill:#ff7f0e;"/>
    </g>
    <g id="patch_19">
-    <path clip-path="url(#p67969da4ac)" d="M 244.413929 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 244.413929 307.584 
 L 249.916549 307.584 
-L 249.916549 301.213618 
-L 244.413929 301.213618 
+L 249.916549 301.247732 
+L 244.413929 301.247732 
 z
 " style="fill:#ff7f0e;"/>
    </g>
    <g id="patch_20">
-    <path clip-path="url(#p67969da4ac)" d="M 271.927026 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 271.927026 307.584 
 L 277.429646 307.584 
-L 277.429646 302.357434 
-L 271.927026 302.357434 
+L 277.429646 302.385423 
+L 271.927026 302.385423 
 z
 " style="fill:#ff7f0e;"/>
    </g>
    <g id="patch_21">
-    <path clip-path="url(#p67969da4ac)" d="M 299.440123 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 299.440123 307.584 
 L 304.942743 307.584 
-L 304.942743 304.688127 
-L 299.440123 304.688127 
+L 304.942743 304.703635 
+L 299.440123 304.703635 
 z
 " style="fill:#ff7f0e;"/>
    </g>
    <g id="patch_22">
-    <path clip-path="url(#p67969da4ac)" d="M 326.95322 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 326.95322 307.584 
 L 332.45584 307.584 
-L 332.45584 303.331696 
-L 326.95322 303.331696 
+L 332.45584 303.354468 
+L 326.95322 303.354468 
 z
 " style="fill:#ff7f0e;"/>
    </g>
    <g id="patch_23">
-    <path clip-path="url(#p67969da4ac)" d="M 354.466317 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 354.466317 307.584 
 L 359.968937 307.584 
-L 359.968937 304.610079 
-L 354.466317 304.610079 
+L 359.968937 304.626004 
+L 354.466317 304.626004 
 z
 " style="fill:#ff7f0e;"/>
    </g>
    <g id="patch_24">
-    <path clip-path="url(#p67969da4ac)" d="M 381.979414 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 381.979414 307.584 
 L 387.482034 307.584 
-L 387.482034 304.338254 
-L 381.979414 304.338254 
+L 387.482034 304.355635 
+L 381.979414 304.355635 
 z
 " style="fill:#ff7f0e;"/>
    </g>
    <g id="patch_25">
-    <path clip-path="url(#p67969da4ac)" d="M 84.837966 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 84.837966 307.584 
 L 90.340586 307.584 
-L 90.340586 303.302092 
-L 84.837966 303.302092 
+L 90.340586 300.747148 
+L 84.837966 300.747148 
 z
 " style="fill:#2ca02c;"/>
    </g>
    <g id="patch_26">
-    <path clip-path="url(#p67969da4ac)" d="M 112.351063 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 112.351063 307.584 
 L 117.853683 307.584 
-L 117.853683 276.886672 
-L 112.351063 276.886672 
+L 117.853683 271.014607 
+L 112.351063 271.014607 
 z
 " style="fill:#2ca02c;"/>
    </g>
    <g id="patch_27">
-    <path clip-path="url(#p67969da4ac)" d="M 139.86416 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 139.86416 307.584 
 L 145.36678 307.584 
-L 145.36678 299.310847 
-L 139.86416 299.310847 
+L 145.36678 295.347802 
+L 139.86416 295.347802 
 z
 " style="fill:#2ca02c;"/>
    </g>
    <g id="patch_28">
-    <path clip-path="url(#p67969da4ac)" d="M 167.377257 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 167.377257 307.584 
 L 172.879877 307.584 
-L 172.879877 289.274872 
-L 167.377257 289.274872 
+L 172.879877 288.727781 
+L 167.377257 288.727781 
 z
 " style="fill:#2ca02c;"/>
    </g>
    <g id="patch_29">
-    <path clip-path="url(#p67969da4ac)" d="M 194.890354 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 194.890354 307.584 
 L 200.392974 307.584 
-L 200.392974 98.707068 
-L 194.890354 98.707068 
+L 200.392974 54.144 
+L 194.890354 54.144 
 z
 " style="fill:#2ca02c;"/>
    </g>
    <g id="patch_30">
-    <path clip-path="url(#p67969da4ac)" d="M 249.916549 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 249.916549 307.584 
 L 255.419168 307.584 
-L 255.419168 234.810395 
-L 249.916549 234.810395 
+L 255.419168 269.970609 
+L 249.916549 269.970609 
 z
 " style="fill:#2ca02c;"/>
    </g>
    <g id="patch_31">
-    <path clip-path="url(#p67969da4ac)" d="M 277.429646 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 277.429646 307.584 
 L 282.932265 307.584 
-L 282.932265 267.593505 
-L 277.429646 267.593505 
+L 282.932265 289.375596 
+L 277.429646 289.375596 
 z
 " style="fill:#2ca02c;"/>
    </g>
    <g id="patch_32">
-    <path clip-path="url(#p67969da4ac)" d="M 304.942743 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 304.942743 307.584 
 L 310.445362 307.584 
-L 310.445362 305.600489 
-L 304.942743 305.600489 
+L 310.445362 305.894864 
+L 304.942743 305.894864 
 z
 " style="fill:#2ca02c;"/>
    </g>
    <g id="patch_33">
-    <path clip-path="url(#p67969da4ac)" d="M 332.45584 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 332.45584 307.584 
 L 337.958459 307.584 
-L 337.958459 54.144 
-L 332.45584 54.144 
+L 337.958459 299.845027 
+L 332.45584 299.845027 
 z
 " style="fill:#2ca02c;"/>
    </g>
    <g id="patch_34">
-    <path clip-path="url(#p67969da4ac)" d="M 359.968937 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 359.968937 307.584 
 L 365.471556 307.584 
-L 365.471556 305.086444 
-L 359.968937 305.086444 
+L 365.471556 304.146836 
+L 359.968937 304.146836 
 z
 " style="fill:#2ca02c;"/>
    </g>
    <g id="patch_35">
-    <path clip-path="url(#p67969da4ac)" d="M 387.482034 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 387.482034 307.584 
 L 392.984653 307.584 
-L 392.984653 282.01635 
-L 387.482034 282.01635 
+L 392.984653 294.670542 
+L 387.482034 294.670542 
 z
 " style="fill:#2ca02c;"/>
    </g>
    <g id="patch_36">
-    <path clip-path="url(#p67969da4ac)" d="M 90.340586 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 90.340586 307.584 
 L 95.843205 307.584 
-L 95.843205 297.892515 
-L 90.340586 297.892515 
+L 95.843205 297.944414 
+L 90.340586 297.944414 
 z
 " style="fill:#d62728;"/>
    </g>
    <g id="patch_37">
-    <path clip-path="url(#p67969da4ac)" d="M 117.853683 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 117.853683 307.584 
 L 123.356302 307.584 
-L 123.356302 268.481644 
-L 117.853683 268.481644 
+L 123.356302 268.691041 
+L 117.853683 268.691041 
 z
 " style="fill:#d62728;"/>
    </g>
    <g id="patch_38">
-    <path clip-path="url(#p67969da4ac)" d="M 145.36678 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 145.36678 307.584 
 L 150.869399 307.584 
-L 150.869399 294.28344 
-L 145.36678 294.28344 
+L 150.869399 294.354665 
+L 145.36678 294.354665 
 z
 " style="fill:#d62728;"/>
    </g>
    <g id="patch_39">
-    <path clip-path="url(#p67969da4ac)" d="M 172.879877 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 172.879877 307.584 
 L 178.382496 307.584 
-L 178.382496 269.633534 
-L 172.879877 269.633534 
+L 178.382496 269.836763 
+L 172.879877 269.836763 
 z
 " style="fill:#d62728;"/>
    </g>
    <g id="patch_40">
-    <path clip-path="url(#p67969da4ac)" d="M 200.392974 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 200.392974 307.584 
 L 205.895593 307.584 
-L 205.895593 290.058049 
-L 200.392974 290.058049 
+L 205.895593 290.151902 
+L 200.392974 290.151902 
 z
 " style="fill:#d62728;"/>
    </g>
    <g id="patch_41">
-    <path clip-path="url(#p67969da4ac)" d="M 255.419168 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 255.419168 307.584 
 L 260.921787 307.584 
-L 260.921787 273.382559 
-L 255.419168 273.382559 
+L 260.921787 273.565711 
+L 255.419168 273.565711 
 z
 " style="fill:#d62728;"/>
    </g>
    <g id="patch_42">
-    <path clip-path="url(#p67969da4ac)" d="M 282.932265 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 282.932265 307.584 
 L 288.434884 307.584 
-L 288.434884 287.611629 
-L 282.932265 287.611629 
+L 288.434884 287.718583 
+L 282.932265 287.718583 
 z
 " style="fill:#d62728;"/>
    </g>
    <g id="patch_43">
-    <path clip-path="url(#p67969da4ac)" d="M 310.445362 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 310.445362 307.584 
 L 315.947982 307.584 
-L 315.947982 303.167525 
-L 310.445362 303.167525 
+L 315.947982 303.191176 
+L 310.445362 303.191176 
 z
 " style="fill:#d62728;"/>
    </g>
    <g id="patch_44">
-    <path clip-path="url(#p67969da4ac)" d="M 337.958459 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 337.958459 307.584 
 L 343.461079 307.584 
-L 343.461079 281.101298 
-L 337.958459 281.101298 
+L 343.461079 281.243115 
+L 337.958459 281.243115 
 z
 " style="fill:#d62728;"/>
    </g>
    <g id="patch_45">
-    <path clip-path="url(#p67969da4ac)" d="M 365.471556 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 365.471556 307.584 
 L 370.974176 307.584 
-L 370.974176 303.506633 
-L 365.471556 303.506633 
+L 370.974176 303.528467 
+L 365.471556 303.528467 
 z
 " style="fill:#d62728;"/>
    </g>
    <g id="patch_46">
-    <path clip-path="url(#p67969da4ac)" d="M 392.984653 307.584 
+    <path clip-path="url(#p3b05b9f86a)" d="M 392.984653 307.584 
 L 398.487273 307.584 
-L 398.487273 291.928524 
-L 392.984653 291.928524 
+L 398.487273 292.012361 
+L 392.984653 292.012361 
 z
 " style="fill:#d62728;"/>
    </g>
@@ -384,10 +384,10 @@ z
       <defs>
        <path d="M 0 0 
 L 0 3.5 
-" id="m61c3ce9532" style="stroke:#000000;stroke-width:0.8;"/>
+" id="m77ec045e3d" style="stroke:#000000;stroke-width:0.8;"/>
       </defs>
       <g>
-       <use style="stroke:#000000;stroke-width:0.8;" x="109.599753" xlink:href="#m61c3ce9532" y="307.584"/>
+       <use style="stroke:#000000;stroke-width:0.8;" x="109.599753" xlink:href="#m77ec045e3d" y="307.584"/>
       </g>
      </g>
      <g id="text_1">
@@ -426,7 +426,7 @@ z
     <g id="xtick_2">
      <g id="line2d_2">
       <g>
-       <use style="stroke:#000000;stroke-width:0.8;" x="164.625948" xlink:href="#m61c3ce9532" y="307.584"/>
+       <use style="stroke:#000000;stroke-width:0.8;" x="164.625948" xlink:href="#m77ec045e3d" y="307.584"/>
       </g>
      </g>
      <g id="text_2">
@@ -458,7 +458,7 @@ z
     <g id="xtick_3">
      <g id="line2d_3">
       <g>
-       <use style="stroke:#000000;stroke-width:0.8;" x="219.652142" xlink:href="#m61c3ce9532" y="307.584"/>
+       <use style="stroke:#000000;stroke-width:0.8;" x="219.652142" xlink:href="#m77ec045e3d" y="307.584"/>
       </g>
      </g>
      <g id="text_3">
@@ -503,7 +503,7 @@ z
     <g id="xtick_4">
      <g id="line2d_4">
       <g>
-       <use style="stroke:#000000;stroke-width:0.8;" x="274.678336" xlink:href="#m61c3ce9532" y="307.584"/>
+       <use style="stroke:#000000;stroke-width:0.8;" x="274.678336" xlink:href="#m77ec045e3d" y="307.584"/>
       </g>
      </g>
      <g id="text_4">
@@ -557,7 +557,7 @@ z
     <g id="xtick_5">
      <g id="line2d_5">
       <g>
-       <use style="stroke:#000000;stroke-width:0.8;" x="329.70453" xlink:href="#m61c3ce9532" y="307.584"/>
+       <use style="stroke:#000000;stroke-width:0.8;" x="329.70453" xlink:href="#m77ec045e3d" y="307.584"/>
       </g>
      </g>
      <g id="text_5">
@@ -607,7 +607,7 @@ z
     <g id="xtick_6">
      <g id="line2d_6">
       <g>
-       <use style="stroke:#000000;stroke-width:0.8;" x="384.730724" xlink:href="#m61c3ce9532" y="307.584"/>
+       <use style="stroke:#000000;stroke-width:0.8;" x="384.730724" xlink:href="#m77ec045e3d" y="307.584"/>
       </g>
      </g>
      <g id="text_6">
@@ -780,10 +780,10 @@ z
       <defs>
        <path d="M 0 0 
 L -3.5 0 
-" id="m14f0d3e4c8" style="stroke:#000000;stroke-width:0.8;"/>
+" id="mdd0da8bc57" style="stroke:#000000;stroke-width:0.8;"/>
       </defs>
       <g>
-       <use style="stroke:#000000;stroke-width:0.8;" x="57.6" xlink:href="#m14f0d3e4c8" y="307.584"/>
+       <use style="stroke:#000000;stroke-width:0.8;" x="57.6" xlink:href="#mdd0da8bc57" y="307.584"/>
       </g>
      </g>
      <g id="text_8">
@@ -807,12 +807,12 @@ z
     <g id="ytick_2">
      <g id="line2d_8">
       <g>
-       <use style="stroke:#000000;stroke-width:0.8;" x="57.6" xlink:href="#m14f0d3e4c8" y="253.757369"/>
+       <use style="stroke:#000000;stroke-width:0.8;" x="57.6" xlink:href="#mdd0da8bc57" y="254.045616"/>
       </g>
      </g>
      <g id="text_9">
       <!-- 0.02 -->
-      <g transform="translate(28.334375 257.556588)scale(0.1 -0.1)">
+      <g transform="translate(28.334375 257.844835)scale(0.1 -0.1)">
        <use xlink:href="#DejaVuSans-48"/>
        <use x="63.623047" xlink:href="#DejaVuSans-46"/>
        <use x="95.410156" xlink:href="#DejaVuSans-48"/>
@@ -823,12 +823,12 @@ z
     <g id="ytick_3">
      <g id="line2d_9">
       <g>
-       <use style="stroke:#000000;stroke-width:0.8;" x="57.6" xlink:href="#m14f0d3e4c8" y="199.930738"/>
+       <use style="stroke:#000000;stroke-width:0.8;" x="57.6" xlink:href="#mdd0da8bc57" y="200.507233"/>
       </g>
      </g>
      <g id="text_10">
       <!-- 0.04 -->
-      <g transform="translate(28.334375 203.729957)scale(0.1 -0.1)">
+      <g transform="translate(28.334375 204.306452)scale(0.1 -0.1)">
        <use xlink:href="#DejaVuSans-48"/>
        <use x="63.623047" xlink:href="#DejaVuSans-46"/>
        <use x="95.410156" xlink:href="#DejaVuSans-48"/>
@@ -839,12 +839,12 @@ z
     <g id="ytick_4">
      <g id="line2d_10">
       <g>
-       <use style="stroke:#000000;stroke-width:0.8;" x="57.6" xlink:href="#m14f0d3e4c8" y="146.104107"/>
+       <use style="stroke:#000000;stroke-width:0.8;" x="57.6" xlink:href="#mdd0da8bc57" y="146.968849"/>
       </g>
      </g>
      <g id="text_11">
       <!-- 0.06 -->
-      <g transform="translate(28.334375 149.903326)scale(0.1 -0.1)">
+      <g transform="translate(28.334375 150.768068)scale(0.1 -0.1)">
        <use xlink:href="#DejaVuSans-48"/>
        <use x="63.623047" xlink:href="#DejaVuSans-46"/>
        <use x="95.410156" xlink:href="#DejaVuSans-48"/>
@@ -855,12 +855,12 @@ z
     <g id="ytick_5">
      <g id="line2d_11">
       <g>
-       <use style="stroke:#000000;stroke-width:0.8;" x="57.6" xlink:href="#m14f0d3e4c8" y="92.277477"/>
+       <use style="stroke:#000000;stroke-width:0.8;" x="57.6" xlink:href="#mdd0da8bc57" y="93.430466"/>
       </g>
      </g>
      <g id="text_12">
       <!-- 0.08 -->
-      <g transform="translate(28.334375 96.076695)scale(0.1 -0.1)">
+      <g transform="translate(28.334375 97.229685)scale(0.1 -0.1)">
        <use xlink:href="#DejaVuSans-48"/>
        <use x="63.623047" xlink:href="#DejaVuSans-46"/>
        <use x="95.410156" xlink:href="#DejaVuSans-48"/>
@@ -1492,7 +1492,7 @@ z
   </g>
  </g>
  <defs>
-  <clipPath id="p67969da4ac">
+  <clipPath id="p3b05b9f86a">
    <rect height="266.112" width="357.12" x="57.6" y="41.472"/>
   </clipPath>
  </defs>
diff --git a/lib/src/sparql/plan_builder.rs b/lib/src/sparql/plan_builder.rs
index 041e8ecc..0f107b06 100644
--- a/lib/src/sparql/plan_builder.rs
+++ b/lib/src/sparql/plan_builder.rs
@@ -934,25 +934,31 @@ fn count_pattern_binds(
     pattern: &TripleOrPathPattern,
     assigned_variables: &HashSet<&Variable>,
 ) -> u8 {
-    let mut count = 3;
+    let mut count = 12;
     if let TermOrVariable::Variable(v) = pattern.subject() {
         if !assigned_variables.contains(v) {
-            count -= 1;
+            count -= 4;
         }
+    } else {
+        count -= 1;
     }
     if let TripleOrPathPattern::Triple(t) = pattern {
         if let NamedNodeOrVariable::Variable(v) = &t.predicate {
             if !assigned_variables.contains(v) {
-                count -= 1;
+                count -= 4;
             }
+        } else {
+            count -= 1;
         }
     } else {
-        count -= 1;
+        count -= 3;
     }
     if let TermOrVariable::Variable(v) = pattern.object() {
         if !assigned_variables.contains(v) {
-            count -= 1;
+            count -= 4;
         }
+    } else {
+        count -= 1;
     }
     count
 }