Comment on xapian scalability.

2 files changed, 317 insertions, 0 deletions

diff --git a/topics/xapian-index-building-scalability.svg b/topics/xapian-index-building-scalability.svg
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+		<text><tspan font-family="Arial" > 1x10</tspan><tspan font-family="Arial"  font-size="9.6" dy="-6.00px">7</tspan><tspan font-size="12.0" dy="6.00"></tspan></text>
+	</g>
+</g>
+<g fill="none" color="black" stroke="currentColor" stroke-width="1.00" stroke-linecap="butt" stroke-linejoin="miter">
+</g>
+<g fill="none" color="black" stroke="currentColor" stroke-width="1.00" stroke-linecap="butt" stroke-linejoin="miter">
+	<path stroke='black'  d='M80.92,54.01 L80.92,422.40 L574.82,422.40 L574.82,54.01 L80.92,54.01 Z  '/></g>
+<g fill="none" color="black" stroke="currentColor" stroke-width="1.00" stroke-linecap="butt" stroke-linejoin="miter">
+	<g transform="translate(19.18,238.21) rotate(270)" stroke="none" fill="black" font-family="Arial" font-size="12.00"  text-anchor="middle">
+		<text><tspan font-family="Arial" >Time (in ms)</tspan></text>
+	</g>
+</g>
+<g fill="none" color="black" stroke="currentColor" stroke-width="1.00" stroke-linecap="butt" stroke-linejoin="miter">
+	<g transform="translate(327.87,471.30)" stroke="none" fill="black" font-family="Arial" font-size="12.00"  text-anchor="middle">
+		<text><tspan font-family="Arial" >Index size (in number of documents)</tspan></text>
+	</g>
+</g>
+<g fill="none" color="black" stroke="currentColor" stroke-width="1.00" stroke-linecap="butt" stroke-linejoin="miter">
+</g>
+	<g id="gnuplot_plot_1" ><title>'xapian-times' using 1:(1000*$2/$1)</title>
+<g fill="none" color="white" stroke="currentColor" stroke-width="2.00" stroke-linecap="butt" stroke-linejoin="miter">
+</g>
+<g fill="none" color="black" stroke="currentColor" stroke-width="2.00" stroke-linecap="butt" stroke-linejoin="miter">
+	<path stroke='black'  d='M80.92,422.05 L130.48,284.78 L180.04,325.51 L229.60,314.53 L279.16,257.71 L328.72,234.14 L378.28,227.15 L427.84,170.55
+		L477.40,114.08 L526.96,78.48  '/>	<use xlink:href='#gpPt0' transform='translate(80.92,422.05) scale(9.00)' color='black'/>
+	<use xlink:href='#gpPt0' transform='translate(130.48,284.78) scale(9.00)' color='black'/>
+	<use xlink:href='#gpPt0' transform='translate(180.04,325.51) scale(9.00)' color='black'/>
+	<use xlink:href='#gpPt0' transform='translate(229.60,314.53) scale(9.00)' color='black'/>
+	<use xlink:href='#gpPt0' transform='translate(279.16,257.71) scale(9.00)' color='black'/>
+	<use xlink:href='#gpPt0' transform='translate(328.72,234.14) scale(9.00)' color='black'/>
+	<use xlink:href='#gpPt0' transform='translate(378.28,227.15) scale(9.00)' color='black'/>
+	<use xlink:href='#gpPt0' transform='translate(427.84,170.55) scale(9.00)' color='black'/>
+	<use xlink:href='#gpPt0' transform='translate(477.40,114.08) scale(9.00)' color='black'/>
+	<use xlink:href='#gpPt0' transform='translate(526.96,78.48) scale(9.00)' color='black'/>
+</g>
+	</g>
+<g fill="none" color="black" stroke="currentColor" stroke-width="2.00" stroke-linecap="butt" stroke-linejoin="miter">
+</g>
+<g fill="none" color="black" stroke="black" stroke-width="1.00" stroke-linecap="butt" stroke-linejoin="miter">
+</g>
+<g fill="none" color="black" stroke="currentColor" stroke-width="1.00" stroke-linecap="butt" stroke-linejoin="miter">
+	<path stroke='black'  d='M80.92,54.01 L80.92,422.40 L574.82,422.40 L574.82,54.01 L80.92,54.01 Z  '/></g>
+<g fill="none" color="black" stroke="currentColor" stroke-width="1.00" stroke-linecap="butt" stroke-linejoin="miter">
+	<g transform="translate(327.87,30.91)" stroke="none" fill="black" font-family="Arial" font-size="12.00"  text-anchor="middle">
+		<text><tspan font-family="Arial" >Time per document to build an index of various sizes</tspan></text>
+	</g>
+</g>
+<g fill="none" color="black" stroke="currentColor" stroke-width="1.00" stroke-linecap="butt" stroke-linejoin="miter">
+</g>
+</g>
+</svg>
+
diff --git a/topics/xapian-scalability.gmi b/topics/xapian-scalability.gmi
new file mode 100644
index 0000000..f6eb768
--- /dev/null
+++ b/topics/xapian-scalability.gmi
@@ -0,0 +1,18 @@
+# Xapian scalability
+
+As the index grows larger, Xapian takes longer to insert new documents. Shown below is the time (in seconds) taken to build indices of various sizes (in number of documents).
+
+* 10k: 5.0009455639999985
+* 20k: 10.747144626
+* 40k: 21.052039352999998
+* 80k: 42.342509834
+* 160k: 87.152875767
+* 320k: 176.353327516
+* 640k: 353.9213599920001
+* 1280k: 727.506412363
+* 2560k: 1494.2583154410001
+* 5120k: 3037.993937756
+
+Notice that it takes 607x, not 512x, more time to build the 5120k index than it takes to build the 10k index. In terms of time, the 10k index takes on average 0.5 ms per document while the 5120k index takes on average 0.59 ms per document. We show this graphically below.
+
+=> xapian-index-building-scalability.svg