Skip to content

P
Postgres FD Implementation
Commit 0ff4352d authored by Peter Eisentraut's avatar Peter Eisentraut
Browse files
Options

Add some real descriptions to the multiargument aggregate functions rather 

than just showing the incomprehensible formulas.
parent 28b14b03
Show whitespace changes
Inline Side-by-side
Showing with 33 additions and 65 deletions
doc/src/sgml/func.sgml
View file @ 0ff4352d
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.344 2006/10/23 18:10:31 petere Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.345 2006/10/23 19:57:37 petere Exp $ -->
<chapter id="functions">
<title>Functions and Operators</title>
......@@ -8102,17 +8102,7 @@ SELECT count(*) FROM sometable;
<entry>
<type>double precision</type>
</entry>
<entry>sqrt((<replaceable class="parameter">N</replaceable> *
sum(<replaceable class="parameter">X</replaceable>*<replaceable
class="parameter">Y</replaceable>) - sum(<replaceable
class="parameter">X</replaceable>) * sum(<replaceable
class="parameter">Y</replaceable>))^2 / ((<replaceable
class="parameter">N</replaceable> * sum(<replaceable
class="parameter">X</replaceable>^2) - sum(<replaceable
class="parameter">X</replaceable>)^2) * (<replaceable
class="parameter">N</replaceable> * sum(<replaceable
class="parameter">Y</replaceable>^2) - sum(<replaceable
class="parameter">Y</replaceable>)^2)))</entry>
<entry>correlation coefficient</entry>
</row>
<row>
......@@ -8129,12 +8119,7 @@ SELECT count(*) FROM sometable;
<entry>
<type>double precision</type>
</entry>
<entry>(sum(<replaceable class="parameter">X</replaceable>*<replaceable
class="parameter">Y</replaceable>) - sum(<replaceable
class="parameter">X</replaceable>) * sum(<replaceable
class="parameter">Y</replaceable>) / <replaceable
class="parameter">N</replaceable>) / <replaceable
class="parameter">N</replaceable></entry>
<entry>population covariance</entry>
</row>
<row>
......@@ -8151,12 +8136,7 @@ SELECT count(*) FROM sometable;
<entry>
<type>double precision</type>
</entry>
<entry>(sum(<replaceable class="parameter">X</replaceable>*<replaceable
class="parameter">Y</replaceable>) - sum(<replaceable
class="parameter">X</replaceable>) * sum(<replaceable
class="parameter">Y</replaceable>) / <replaceable
class="parameter">N</replaceable>) / (<replaceable
class="parameter">N</replaceable> - 1)</entry>
<entry>sample covariance</entry>
</row>
<row>
......@@ -8169,8 +8149,8 @@ SELECT count(*) FROM sometable;
<entry>
<type>double precision</type>
</entry>
<entry>sum(<replaceable class="parameter">X</replaceable>) /
<replaceable class="parameter">N</replaceable></entry>
<entry>average of the independent variable
(<literal>sum(<replaceable class="parameter">X</replaceable>)/<replaceable class="parameter">N</replaceable></literal>)</entry>
</row>
<row>
......@@ -8183,8 +8163,8 @@ SELECT count(*) FROM sometable;
<entry>
<type>double precision</type>
</entry>
<entry>sum(<replaceable class="parameter">Y</replaceable>) /
<replaceable class="parameter">N</replaceable></entry>
<entry>average of the dependent variable
(<literal>sum(<replaceable class="parameter">Y</replaceable>)/<replaceable class="parameter">N</replaceable></literal>)</entry>
</row>
<row>
......@@ -8197,7 +8177,7 @@ SELECT count(*) FROM sometable;
<entry>
<type>bigint</type>
</entry>
<entry>number of input rows in which both expressions are non-null</entry>
<entry>number of input rows in which both expressions are nonnull</entry>
</row>
<row>
......@@ -8213,14 +8193,10 @@ SELECT count(*) FROM sometable;
<entry>
<type>double precision</type>
</entry>
<entry>(sum(<replaceable class="parameter">Y</replaceable>) *
sum(<replaceable class="parameter">X</replaceable>^2) - sum(<replaceable
class="parameter">X</replaceable>) * sum(<replaceable
class="parameter">X</replaceable>*<replaceable
class="parameter">Y</replaceable>)) / (<replaceable
class="parameter">N</replaceable> * sum(<replaceable
class="parameter">X</replaceable>^2) - sum(<replaceable
class="parameter">X</replaceable>)^2)</entry>
<entry>y-intercept of the least-squares-fit linear equation
determined by the (<replaceable
class="parameter">X</replaceable>, <replaceable
class="parameter">Y</replaceable>) pairs</entry>
</row>
<row>
......@@ -8233,17 +8209,7 @@ SELECT count(*) FROM sometable;
<entry>
<type>double precision</type>
</entry>
<entry>(<replaceable class="parameter">N</replaceable> *
sum(<replaceable class="parameter">X</replaceable>*<replaceable
class="parameter">Y</replaceable>) - sum(<replaceable
class="parameter">X</replaceable>) * sum(<replaceable
class="parameter">Y</replaceable>))^2 / ((<replaceable
class="parameter">N</replaceable> * sum(<replaceable
class="parameter">X</replaceable>^2) - sum(<replaceable
class="parameter">X</replaceable>)^2) * (<replaceable
class="parameter">N</replaceable> * sum(<replaceable
class="parameter">Y</replaceable>^2) - sum(<replaceable
class="parameter">Y</replaceable>)^2))</entry>
<entry>square of the correlation coefficient</entry>
</row>
<row>
......@@ -8259,14 +8225,9 @@ SELECT count(*) FROM sometable;
<entry>
<type>double precision</type>
</entry>
<entry>(<replaceable class="parameter">N</replaceable> *
sum(<replaceable class="parameter">X</replaceable>*<replaceable
class="parameter">Y</replaceable>) - sum(<replaceable
class="parameter">X</replaceable>) * sum(<replaceable
class="parameter">Y</replaceable>)) / (<replaceable
class="parameter">N</replaceable> * sum(<replaceable
class="parameter">X</replaceable>^2) - sum(<replaceable
class="parameter">X</replaceable>)^2)</entry>
<entry>slope of the least-squares-fit linear equation determined
by the (<replaceable class="parameter">X</replaceable>,
<replaceable class="parameter">Y</replaceable>) pairs</entry>
</row>
<row>
......@@ -8279,9 +8240,11 @@ SELECT count(*) FROM sometable;
<entry>
<type>double precision</type>
</entry>
<entry>sum(<replaceable class="parameter">X</replaceable>^2) -
sum(<replaceable class="parameter">X</replaceable>)^2 / <replaceable
class="parameter">N</replaceable></entry>
<entry><literal>sum(<replaceable
class="parameter">X</replaceable>^2) - sum(<replaceable
class="parameter">X</replaceable>)^2/<replaceable
class="parameter">N</replaceable></literal> (<quote>sum of
squares</quote> of the independent variable)</entry>
</row>
<row>
......@@ -8294,11 +8257,14 @@ SELECT count(*) FROM sometable;
<entry>
<type>double precision</type>
</entry>
<entry>sum(<replaceable class="parameter">X</replaceable>*<replaceable
<entry><literal>sum(<replaceable
class="parameter">X</replaceable>*<replaceable
class="parameter">Y</replaceable>) - sum(<replaceable
class="parameter">X</replaceable>) * sum(<replaceable
class="parameter">Y</replaceable>) / <replaceable
class="parameter">N</replaceable></entry>
class="parameter">Y</replaceable>)/<replaceable
class="parameter">N</replaceable></literal> (<quote>sum of
products</quote> of independent times dependent
variable)</entry>
</row>
<row>
......@@ -8311,9 +8277,11 @@ SELECT count(*) FROM sometable;
<entry>
<type>double precision</type>
</entry>
<entry>sum(<replaceable class="parameter">Y</replaceable>^2) -
sum(<replaceable class="parameter">Y</replaceable>)^2 / <replaceable
class="parameter">N</replaceable></entry>
<entry><literal>sum(<replaceable
class="parameter">Y</replaceable>^2) - sum(<replaceable
class="parameter">Y</replaceable>)^2/<replaceable
class="parameter">N</replaceable></literal> (<quote>sum of
squares</quote> of the dependent variable)</entry>
</row>
<row>
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment