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<b>KeysCommand: Contents</b><br> <a href="#KEYS _pattern_">KEYS _pattern_</a><br> <a href="#Return value">Return value</a><br> <a href="#See also">See also</a>
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<h1 class="wikiname">KeysCommand</h1>
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<h1><a name="KEYS _pattern_">KEYS _pattern_</a></h1>
<i>Time complexity: O(n) (with n being the number of keys in the DB, and assuming keys and pattern of limited length)</i><blockquote>Returns all the keys matching the glob-style <i>pattern</i> asspace separated strings. For example if you have in thedatabase the keys "foo" and "foobar" the command "KEYS foo<code name="code" class="python">*</code>"will return "foo foobar".</blockquote>
<blockquote>Note that while the time complexity for this operation is O(n)the constant times are pretty low. For example Redis runningon an entry level laptop can scan a 1 million keys databasein 40 milliseconds. Still it's better to consider this one ofthe slow commands that may ruin the DB performance if not usedwith care.</blockquote>
Glob style patterns examples:
<ul><li> h?llo will match hello hallo hhllo</li><li> h<b>llo will match hllo heeeello
<blockquote>* h<a href="ae.html">ae</a>llo will match hello and hallo, but not hillo</blockquote>Use \ to escape special chars if you want to match them verbatim.<h2><a name="Return value">Return value</a></h2><a href="ReplyTypes.html">Bulk reply</a>, specifically a string in the form of space separated list of keys. Note that most client libraries will return an Array of keys and not a single string with space separated keys (that is, split by " " is performed in the client library usually).<h2><a name="See also">See also</a></h2>
<blockquote>* <a href="RandomkeyCommand.html">RANDOMKEY</a> to get the name of a randomly selected key in O(1).</blockquote></b></li></ul>
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