<!-- 
RSS generated by JIRA (9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66) at Thu Feb 08 04:55:35 UTC 2024

It is possible to restrict the fields that are returned in this document by specifying the 'field' parameter in your request.
For example, to request only the issue key and summary append 'field=key&field=summary' to the URL of your request.
-->
<rss version="0.92" >
<channel>
    <title>MongoDB Jira</title>
    <link>https://jira.mongodb.org</link>
    <description>This file is an XML representation of an issue</description>
    <language>en-us</language>    <build-info>
        <version>9.7.1</version>
        <build-number>970001</build-number>
        <build-date>13-04-2023</build-date>
    </build-info>


<item>
            <title>[SERVER-40636] $expr inside $match does not use indexes in many cases</title>
                <link>https://jira.mongodb.org/browse/SERVER-40636</link>
                <project id="10000" key="SERVER">Core Server</project>
                    <description>&lt;p&gt;&lt;b&gt;Related issues:&lt;/b&gt;&lt;/p&gt;
&lt;ul&gt;
	&lt;li&gt;&lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-32549&quot; title=&quot;allow $expr with $in expression use a non-multikey index&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-32549&quot;&gt;SERVER-32549&lt;/a&gt;**&lt;/li&gt;
	&lt;li&gt;&lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-38138&quot; title=&quot;$expr doesn&amp;#39;t use indexes&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-38138&quot;&gt;&lt;del&gt;SERVER-38138&lt;/del&gt;&lt;/a&gt;&lt;br/&gt;
**&lt;/li&gt;
&lt;/ul&gt;


&lt;p&gt;&lt;b&gt;Summary:&lt;/b&gt;&lt;br/&gt;
**$expr inside $match stage seems to only respect index when using $eq operator. Other operators (e.g. $gt, $gte, $lt, $lte, $indexOfCP) would result collection scan.&lt;/p&gt;


&lt;p&gt;I decided to create separate ticket because it looks to me as a bug rather than enhancement, since $expr operator within $match stage have no alternatives sometimes and for large datasets it becomes unusable if index is ignored.&lt;/p&gt;


&lt;p&gt;&lt;a href=&quot;https://docs.mongodb.com/manual/reference/operator/query/expr/#behavior&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;Documentation&lt;/a&gt; states that &quot;&lt;em&gt;$expr does not support multikey indexes&quot;&lt;/em&gt; which probably implies that is should support single field indexes.&lt;/p&gt;

&lt;p&gt;Tested with ascending index on a single field for date, int and string for $gt, $gte, $lt, $lte, $indexOfCP operators. Both find and aggregate would result collection scan. Only $eq would result ixscan.&lt;/p&gt;

&lt;p&gt;Tested on community version 4.0.8 / 4.0.9 and enterprise version 4.0.8, against single instance and replica set (distmod: &quot;rhel70&quot;).&lt;/p&gt;

&lt;p&gt;&#160;&lt;/p&gt;

&lt;p&gt;&#160;&lt;/p&gt;

&lt;p&gt;&lt;b&gt;Steps to reproduce:&lt;/b&gt;&lt;/p&gt;

&lt;p&gt;&#160;&lt;/p&gt;

&lt;p&gt;Sample set:&lt;/p&gt;
&lt;p/&gt;
&lt;div id=&quot;syntaxplugin&quot; class=&quot;syntaxplugin&quot; style=&quot;border: 1px dashed #bbb; border-radius: 5px !important; overflow: auto; max-height: 30em;&quot;&gt;
&lt;table cellspacing=&quot;0&quot; cellpadding=&quot;0&quot; border=&quot;0&quot; width=&quot;100%&quot; style=&quot;font-size: 1em; line-height: 1.4em !important; font-weight: normal; font-style: normal; color: black;&quot;&gt;
		&lt;tbody &gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;  margin-top: 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: #006699; font-weight: bold; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;const&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt; size = &lt;/span&gt;&lt;span style=&quot;color: #009900; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;100000&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;;&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;[...&lt;/span&gt;&lt;span style=&quot;color: #006699; font-weight: bold; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;new&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt; Array(size)].map((x, i) =&amp;gt; ({&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;    num: i,&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;    str: &lt;/span&gt;&lt;span style=&quot;color: blue; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;&apos;val_&apos;&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt; + i,&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;    date: &lt;/span&gt;&lt;span style=&quot;color: #006699; font-weight: bold; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;new&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt; Date(&lt;/span&gt;&lt;span style=&quot;color: #006699; font-weight: bold; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;new&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt; Date() + (size/&lt;/span&gt;&lt;span style=&quot;color: #009900; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;2&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt; - i)*&lt;/span&gt;&lt;span style=&quot;color: #009900; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;1000&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;*&lt;/span&gt;&lt;span style=&quot;color: #009900; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;60&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;)&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   margin-bottom: 10px;  width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;})) &lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
			&lt;/tbody&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;p/&gt;
&lt;p&gt;&#160;&lt;/p&gt;

&lt;p&gt;Index definitions:&lt;/p&gt;
&lt;p/&gt;
&lt;div id=&quot;syntaxplugin&quot; class=&quot;syntaxplugin&quot; style=&quot;border: 1px dashed #bbb; border-radius: 5px !important; overflow: auto; max-height: 30em;&quot;&gt;
&lt;table cellspacing=&quot;0&quot; cellpadding=&quot;0&quot; border=&quot;0&quot; width=&quot;100%&quot; style=&quot;font-size: 1em; line-height: 1.4em !important; font-weight: normal; font-style: normal; color: black;&quot;&gt;
		&lt;tbody &gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;  margin-top: 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;createIndex({num: &lt;/span&gt;&lt;span style=&quot;color: #009900; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;1&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;},  {name: `${colName}_num_asc` });&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;createIndex({str: &lt;/span&gt;&lt;span style=&quot;color: #009900; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;1&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;},  {name: `${colName}_str_asc` });&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   margin-bottom: 10px;  width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;createIndex({date: &lt;/span&gt;&lt;span style=&quot;color: #009900; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;1&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;}, {name: `${colName}_date_asc` });&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
			&lt;/tbody&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;p/&gt;
&lt;p&gt;&#160;&lt;br/&gt;
Find query:&lt;/p&gt;
&lt;p/&gt;
&lt;div id=&quot;syntaxplugin&quot; class=&quot;syntaxplugin&quot; style=&quot;border: 1px dashed #bbb; border-radius: 5px !important; overflow: auto; max-height: 30em;&quot;&gt;
&lt;table cellspacing=&quot;0&quot; cellpadding=&quot;0&quot; border=&quot;0&quot; width=&quot;100%&quot; style=&quot;font-size: 1em; line-height: 1.4em !important; font-weight: normal; font-style: normal; color: black;&quot;&gt;
		&lt;tbody &gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;  margin-top: 10px;   margin-bottom: 10px;  width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;find({$expr: {$gt: [&lt;/span&gt;&lt;span style=&quot;color: blue; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;&apos;$num&apos;&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;, &lt;/span&gt;&lt;span style=&quot;color: #009900; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;90000&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;]}}, {explain: &lt;/span&gt;&lt;span style=&quot;color: #006699; font-weight: bold; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;true&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;}).limit(&lt;/span&gt;&lt;span style=&quot;color: #009900; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;5&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;)&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
			&lt;/tbody&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;p/&gt;
&lt;p&gt;&#160;&lt;/p&gt;

&lt;p&gt;Aggregation:&lt;/p&gt;
&lt;p/&gt;
&lt;div id=&quot;syntaxplugin&quot; class=&quot;syntaxplugin&quot; style=&quot;border: 1px dashed #bbb; border-radius: 5px !important; overflow: auto; max-height: 30em;&quot;&gt;
&lt;table cellspacing=&quot;0&quot; cellpadding=&quot;0&quot; border=&quot;0&quot; width=&quot;100%&quot; style=&quot;font-size: 1em; line-height: 1.4em !important; font-weight: normal; font-style: normal; color: black;&quot;&gt;
		&lt;tbody &gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;  margin-top: 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;aggregate(&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;  [{$match: {$expr: {$gt: [&lt;/span&gt;&lt;span style=&quot;color: blue; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;&apos;$num&apos;&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;, &lt;/span&gt;&lt;span style=&quot;color: #009900; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;90000&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;]}}}, {$limit: &lt;/span&gt;&lt;span style=&quot;color: #009900; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;5&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;}], &lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   margin-bottom: 10px;  width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;  { explain: &lt;/span&gt;&lt;span style=&quot;color: #006699; font-weight: bold; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;true&lt;/span&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt; }) &lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
			&lt;/tbody&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;p/&gt;
&lt;p&gt;&#160;&lt;/p&gt;

&lt;p&gt;&lt;b&gt;Expected result:&lt;/b&gt; &lt;br/&gt;
ixscan&lt;/p&gt;

&lt;p&gt;&lt;b&gt;Actual result:&lt;/b&gt; &lt;br/&gt;
collscan&lt;/p&gt;

&lt;p&gt;&lt;b&gt;Details:&lt;/b&gt; &lt;br/&gt;
Explained and profiled queries are attached.&lt;br/&gt;
&apos;&lt;em&gt;Good-*&lt;/em&gt;&apos; attachements - result of $eq operator.&lt;br/&gt;
&apos;&lt;em&gt;Bad-*&lt;/em&gt;&apos; attachments - result of $gt operator.&lt;/p&gt;

&lt;p&gt;&#160;&lt;/p&gt;

&lt;p&gt;&#160;&lt;/p&gt;</description>
                <environment></environment>
        <key id="738131">SERVER-40636</key>
            <summary>$expr inside $match does not use indexes in many cases</summary>
                <type id="4" iconUrl="https://jira.mongodb.org/secure/viewavatar?size=xsmall&amp;avatarId=14710&amp;avatarType=issuetype">Improvement</type>
                                            <priority id="3" iconUrl="https://jira.mongodb.org/images/icons/priorities/major.svg">Major - P3</priority>
                        <status id="6" iconUrl="https://jira.mongodb.org/images/icons/statuses/closed.png" description="The issue is considered finished, the resolution is correct. Issues which are closed can be reopened.">Closed</status>
                    <statusCategory id="3" key="done" colorName="success"/>
                                    <resolution id="3">Duplicate</resolution>
                                        <assignee username="asya.kamsky@mongodb.com">Asya Kamsky</assignee>
                                    <reporter username="egor.elagin">Egor Elagin</reporter>
                        <labels>
                    </labels>
                <created>Sat, 13 Apr 2019 15:32:28 +0000</created>
                <updated>Mon, 3 Jun 2019 14:06:48 +0000</updated>
                            <resolved>Mon, 3 Jun 2019 14:06:48 +0000</resolved>
                                                                    <component>Querying</component>
                                        <votes>0</votes>
                                    <watches>8</watches>
                                                                                                                <comments>
                            <comment id="2268505" author="asya" created="Mon, 3 Jun 2019 14:06:48 +0000"  >&lt;p&gt;It&apos;s only correct to use index for $gt/$lt when $expr bounds it to same type (either by having two bounds of same type, or by having $type test for same type that is being compared to) because our index matching is type bracketed same as the find semantics.   Aggregation comparison semantics are not so using an index would not give correct results if there&apos;s just a $gt or $lt expression.&lt;/p&gt;

&lt;p&gt;Closing as duplicate of &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-34926&quot; title=&quot;allow $expr with comparison bounded on both sides with same type to use a non-multikey index&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-34926&quot;&gt;&lt;del&gt;SERVER-34926&lt;/del&gt;&lt;/a&gt; which is tracking using index with $expr comparisons when it&apos;s correct.&lt;/p&gt;</comment>
                            <comment id="2237438" author="craig.homa" created="Tue, 7 May 2019 18:08:25 +0000"  >&lt;p&gt;&lt;a href=&quot;https://jira.mongodb.org/secure/ViewProfile.jspa?name=asya&quot; class=&quot;user-hover&quot; rel=&quot;asya&quot;&gt;asya&lt;/a&gt; to investigate if this is in fact, a duplicate. &lt;/p&gt;</comment>
                            <comment id="2217273" author="asya" created="Wed, 17 Apr 2019 23:00:39 +0000"  >&lt;p&gt;&lt;a href=&quot;https://jira.mongodb.org/secure/ViewProfile.jspa?name=egor.elagin&quot; class=&quot;user-hover&quot; rel=&quot;egor.elagin&quot;&gt;egor.elagin&lt;/a&gt; aggregation semantics (which is what $expr uses) are different from find/match semantics which is what indexes support.  If we used the index for $gt (as an example) we would not get the same results as without the index (for instance if the value had other types than the one being compared to).&lt;/p&gt;</comment>
                            <comment id="2214481" author="eric.sedor" created="Tue, 16 Apr 2019 00:40:57 +0000"  >&lt;p&gt;Thanks &lt;a href=&quot;https://jira.mongodb.org/secure/ViewProfile.jspa?name=egor.elagin&quot; class=&quot;user-hover&quot; rel=&quot;egor.elagin&quot;&gt;egor.elagin&lt;/a&gt;. We will look into this.&lt;/p&gt;</comment>
                            <comment id="2212819" author="egor.elagin" created="Sun, 14 Apr 2019 19:58:41 +0000"  >&lt;p&gt;Update: it&apos;s definitely not a Major-P3 priority, and most probably not a bug. I think match inside $expr wasn&apos;t designed to use index from the beginning, `$eq` is special case, since it has &lt;a href=&quot;https://github.com/mongodb/mongo/commit/9282f7813d97756f0ab1e635d57e84b7145560d7&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;custom optimization&lt;/a&gt; to use index.&lt;/p&gt;</comment>
                    </comments>
                <issuelinks>
                            <issuelinktype id="10010">
                    <name>Duplicate</name>
                                            <outwardlinks description="duplicates">
                                        <issuelink>
            <issuekey id="542069">SERVER-34926</issuekey>
        </issuelink>
                            </outwardlinks>
                                                        </issuelinktype>
                    </issuelinks>
                <attachments>
                            <attachment id="213982" name="bad-aggr-query-explained.json" size="1657" author="egor.elagin" created="Sat, 13 Apr 2019 15:17:13 +0000"/>
                            <attachment id="213983" name="bad-aggr-query-info.json" size="1267" author="egor.elagin" created="Sat, 13 Apr 2019 15:17:11 +0000"/>
                            <attachment id="213984" name="bad-find-query-explained.json" size="2880" author="egor.elagin" created="Sat, 13 Apr 2019 15:17:08 +0000"/>
                            <attachment id="213985" name="bad-find-query-info.json" size="2102" author="egor.elagin" created="Sat, 13 Apr 2019 15:16:50 +0000"/>
                            <attachment id="213980" name="good-aggr-query-explained.json" size="3004" author="egor.elagin" created="Sat, 13 Apr 2019 15:18:33 +0000"/>
                            <attachment id="213981" name="good-aggr-query-info.json" size="1276" author="egor.elagin" created="Sat, 13 Apr 2019 15:18:29 +0000"/>
                    </attachments>
                <subtasks>
                    </subtasks>
                <customfields>
                                                <customfield id="customfield_10050" key="com.atlassian.jira.toolkit:comments">
                        <customfieldname># Replies</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>5.0</customfieldvalue>
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                <customfield id="customfield_10055" key="com.atlassian.jira.ext.charting:firstresponsedate">
                        <customfieldname>Date of 1st Reply</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>Tue, 16 Apr 2019 00:40:57 +0000</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10052" key="com.atlassian.jira.toolkit:dayslastcommented">
                        <customfieldname>Days since reply</customfieldname>
                        <customfieldvalues>
                                        4 years, 36 weeks, 2 days ago
    
                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_18254" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname>Dependencies</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue><![CDATA[]]></customfieldvalue>


                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_15850" key="com.atlassian.jira.plugins.jira-development-integration-plugin:devsummary">
                        <customfieldname>Development</customfieldname>
                        <customfieldvalues>
                            
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        <customfield id="customfield_10057" key="com.atlassian.jira.toolkit:lastusercommented">
                        <customfieldname>Last comment by Customer</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>true</customfieldvalue>
                        </customfieldvalues>
                    </customfield>
                                                                                            <customfield id="customfield_10056" key="com.atlassian.jira.toolkit:lastupdaterorcommenter">
                        <customfieldname>Last commenter</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>asya.kamsky@mongodb.com</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_11151" key="com.atlassian.jira.toolkit:LastCommentDate">
                        <customfieldname>Last public comment date</customfieldname>
                        <customfieldvalues>
                            4 years, 36 weeks, 2 days ago
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                    <customfield id="customfield_10051" key="com.atlassian.jira.toolkit:participants">
                        <customfieldname>Participants</customfieldname>
                        <customfieldvalues>
                                        <customfieldvalue>asya.kamsky@mongodb.com</customfieldvalue>
            <customfieldvalue>craig.homa@mongodb.com</customfieldvalue>
            <customfieldvalue>egor.elagin</customfieldvalue>
            <customfieldvalue>eric.sedor@mongodb.com</customfieldvalue>
    
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                        <customfield id="customfield_14254" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Product Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1|huugan:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                <customfield id="customfield_12550" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>2|hujx9j:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10558" key="com.pyxis.greenhopper.jira:gh-global-rank">
                        <customfieldname>Rank (Obsolete)</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>9223372036854775807</customfieldvalue>
                        </customfieldvalues>
                    </customfield>
                                                                                            <customfield id="customfield_23361" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname>Requested By</customfieldname>
                        <customfieldvalues>
                                

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                <customfield id="customfield_10053" key="com.atlassian.jira.ext.charting:timeinstatus">
                        <customfieldname>Time In Status</customfieldname>
                        <customfieldvalues>
                            
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        <customfield id="customfield_22870" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname>Triagers</customfieldname>
                        <customfieldvalues>
                                    <customfieldvalue><![CDATA[eric.sedor@mongodb.com]]></customfieldvalue>
    

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                    <customfield id="customfield_14350" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>serverRank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1|huu2jz:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                    </customfields>
    </item>
</channel>
</rss>