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Commit91199dd

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doc: Reword unexplained abbreviation
The previous wording used MVF to indicate the Most Common Values'Frequencies, but the abbreviation was never explained or defined.Reword to mcv_freqs to make the use clearer.Also add MCF and MCV as acronyms as they were using <acronym>markup but were missing from the acronyms page.Reported-by: Eric Mutta <eric.mutta@gmail.com>Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>Discussion:https://postgr.es/m/166112292492.654.5377188452604176150@wrigleys.postgresql.org
1 parent5f38a20 commit91199dd

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‎doc/src/sgml/acronyms.sgml

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@@ -408,6 +408,26 @@
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><acronym>MCF</acronym></term>
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<listitem>
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<para>
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Most Common Frequency, that is the frequency associated with some
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Most Common Value
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><acronym>MCV</acronym></term>
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<listitem>
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<para>
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Most Common Value, one of the values appearing most often within a
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particular table column
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><acronym>MITM</acronym></term>
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<listitem>

‎doc/src/sgml/planstats.sgml

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@@ -203,7 +203,7 @@ EXPLAIN SELECT * FROM tenk1 WHERE stringu1 = 'xxx';
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<acronym>MCV</acronym>s:
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<programlisting>
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selectivity = (1 - sum(mvf))/(num_distinct - num_mcv)
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selectivity = (1 - sum(mcv_freqs))/(num_distinct - num_mcv)
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= (1 - (0.00333333 + 0.003 + 0.003 + 0.003 + 0.003 + 0.003 +
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0.003 + 0.003 + 0.003 + 0.003))/(676 - 10)
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= 0.0014559

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