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$Header: /cvsroot/pgsql/doc/src/sgml/Attic/oper.sgml,v 1.15 2000/03/31 03:27:41 thomas Exp $
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 <Chapter Id="operators">
  <Title id="operators-title">Operators</Title>

  <Abstract>
   <Para>
    Describes the built-in operators available in 
    <ProductName>Postgres</ProductName>.
   </Para>
  </Abstract>

  <Para>
   <ProductName>Postgres</ProductName> provides a large number of 
   built-in operators on system types.
   These operators are declared in the system catalog
   <literal>pg_operator</literal>.  Every entry in <literal>pg_operator</literal> includes
   the name of the procedure that implements the operator and the
   class <Acronym>OIDs</Acronym> of the input and output types.
  </Para>

  <Para>
   To view all variations of the <Quote>||</Quote> string concatenation operator, 
   try
   <ProgramListing>
    SELECT oprleft, oprright, oprresult, oprcode
    FROM pg_operator WHERE oprname = '||';

oprleft|oprright|oprresult|oprcode
-------+--------+---------+-------
     25|      25|       25|textcat
   1042|    1042|     1042|textcat
   1043|    1043|     1043|textcat
(3 rows)
   </ProgramListing>
  </Para>

  <Para>
   Users may invoke operators using the operator name, as in:

   <ProgramListing>
select * from emp where salary < 40000;
   </ProgramListing>

   Alternatively, users may call the functions that implement the
   operators directly.  In this case, the query above would be expressed
   as:
   <ProgramListing>
select * from emp where int4lt(salary, 40000);
   </ProgramListing>
  </Para>

  <Para>
   <Application>psql</Application>
   has a command (<Command>\dd</Command>) to show these operators.
  </Para>

  <sect1>
   <title>Lexical Precedence</title>

   <para>
    Operators have a precedence which is currently hardcoded into the parser.
    Most operators have the same precedence and are left-associative. This may lead
    to non-intuitive behavior; for example the boolean operators "&lt;" and "&gt;"
    have a different precedence than the boolean operators "&lt;=" and "&gt;=".

<table tocentry="1">
<title>
Operator Ordering (decreasing precedence)
</title>

<tgroup cols="2">
<thead>
<row>
<entry>
Element
</entry>
<entry>
Precedence
</entry>
<entry>
Description
</entry>
</row>
</thead>

<tbody>
<row>
<entry>
UNION
</entry>
<entry>
left
</entry>
<entry>
SQL select construct
</entry>
</row>
<row>
<entry>
::
</entry>
<entry>
</entry>
<entry>
<productname>Postgres</productname> typecasting
</entry>
</row>
<row>
<entry>
[ ]
</entry>
<entry>
left
</entry>
<entry>
array delimiters
</entry>
</row>
<row>
<entry>
.
</entry>
<entry>
left
</entry>
<entry>
table/column delimiter
</entry>
</row>
<row>
<entry>
-
</entry>
<entry>
right
</entry>
<entry>
unary minus
</entry>
</row>
<row>
<entry>
;
</entry>
<entry>
left
</entry>
<entry>
statement termination, logarithm
</entry>
</row>
<row>
<entry>
:
</entry>
<entry>
right
</entry>
<entry>
exponentiation
</entry>
</row>
<row>
<entry>
|
</entry>
<entry>
left
</entry>
<entry>
start of interval
</entry>
</row>
<row>
<entry>
* / %
</entry>
<entry>
left
</entry>
<entry>
multiplication, division, modulo
</entry>
</row>
<row>
<entry>
+ -
</entry>
<entry>
left
</entry>
<entry>
addition, subtraction
</entry>
</row>
<row>
<entry>
IS
</entry>
<entry>
</entry>
<entry>
test for TRUE, FALSE, NULL
</entry>
</row>
<row>
<entry>
ISNULL
</entry>
<entry>
</entry>
<entry>
test for NULL
</entry>
</row>
<row>
<entry>
NOTNULL
</entry>
<entry>
</entry>
<entry>
test for NOT NULL
</entry>
</row>
<row>
<entry>
(all other operators)
</entry>
<entry>
</entry>
<entry>
native and user-defined
</entry>
</row>
<row>
<entry>
IN
</entry>
<entry>
</entry>
<entry>
set membership
</entry>
</row>
<row>
<entry>
BETWEEN
</entry>
<entry>
</entry>
<entry>
containment
</entry>
</row>
<row>
<entry>
OVERLAPS
</entry>
<entry>
</entry>
<entry>
time interval overlap
</entry>
</row>
<row>
<entry>
LIKE
</entry>
<entry>
</entry>
<entry>
string pattern matching
</entry>
</row>
<row>
<entry>
&lt; &gt;
</entry>
<entry>
</entry>
<entry>
boolean inequality
</entry>
</row>
<row>
<entry>
=
</entry>
<entry>
right
</entry>
<entry>
equality
</entry>
</row>
<row>
<entry>
NOT
</entry>
<entry>
right
</entry>
<entry>
negation
</entry>
</row>
<row>
<entry>
AND
</entry>
<entry>
left
</entry>
<entry>
logical intersection
</entry>
</row>
<row>
<entry>
OR
</entry>
<entry>
left
</entry>
<entry>
logical union
</entry>
</row>
</tbody>
</tgroup>
</table>
</para>
</sect1>

  <sect1>
   <title>General Operators</title>

   <para>
    The operators listed here are defined for a number of native data types, 
    ranging from numeric types to data/time types.
   </para>

   <Para>
    <TABLE TOCENTRY="1">
     <TITLE><ProductName>Postgres</ProductName> Operators</TITLE>
     <TITLEABBREV>Operators</TITLEABBREV>
     <TGROUP COLS="3">
      <THEAD>
       <ROW>
	<ENTRY>Operator</ENTRY>
	<ENTRY>Description</ENTRY>
	<ENTRY>Usage</ENTRY>
       </ROW>
      </THEAD>
      <TBODY>
       <ROW>
	<ENTRY> &lt; </ENTRY>
	<ENTRY>Less than?</ENTRY>
	<ENTRY>1 &lt; 2</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;= </ENTRY>
	<ENTRY>Less than or equal to?</ENTRY>
	<ENTRY>1 &lt;= 2</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;&gt; </ENTRY>
	<ENTRY>Not equal?</ENTRY>
	<ENTRY>1 &lt;&gt; 2</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> = </ENTRY>
	<ENTRY>Equal?</ENTRY>
	<ENTRY>1 = 1</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &gt; </ENTRY>
	<ENTRY>Greater than?</ENTRY>
	<ENTRY>2 &gt; 1</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &gt;= </ENTRY>
	<ENTRY>Greater than or equal to?</ENTRY>
	<ENTRY>2 &gt;= 1</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> || </ENTRY>
	<ENTRY>Concatenate strings</ENTRY>
	<ENTRY>'Postgre' || 'SQL'</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> !!= </ENTRY>
	<ENTRY>NOT IN</ENTRY>
	<ENTRY>3 !!= i</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> ~~ </ENTRY>
	<ENTRY>LIKE</ENTRY>
	<ENTRY>'scrappy,marc,hermit' ~~ '%scrappy%'</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> !~~ </ENTRY>
	<ENTRY>NOT LIKE</ENTRY>
	<ENTRY>'bruce' !~~ '%al%'</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> ~ </ENTRY>
	<ENTRY>Match (regex), case sensitive</ENTRY>
	<ENTRY>'thomas' ~ '.*thomas.*'</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> ~* </ENTRY>
	<ENTRY>Match (regex), case insensitive</ENTRY>
	<ENTRY>'thomas' ~* '.*Thomas.*'</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> !~ </ENTRY>
	<ENTRY>Does not match (regex), case sensitive</ENTRY>
	<ENTRY>'thomas' !~ '.*Thomas.*'</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> !~* </ENTRY>
	<ENTRY>Does not match (regex), case insensitive</ENTRY>
	<ENTRY>'thomas' !~* '.*vadim.*'</ENTRY>
       </ROW>
      </TBODY>
     </TGROUP>
    </TABLE>
   </Para>
  </sect1>

  <sect1>
   <title id="math-opers">Numerical Operators</title>

   <Para>
    <TABLE TOCENTRY="1">
     <TITLE><ProductName>Postgres</ProductName> Numerical Operators</TITLE>
     <TITLEABBREV>Operators</TITLEABBREV>
     <TGROUP COLS="3">
      <THEAD>
       <ROW>
	<ENTRY>Operator</ENTRY>
	<ENTRY>Description</ENTRY>
	<ENTRY>Usage</ENTRY>
       </ROW>
      </THEAD>
      <TBODY>
       <ROW>
	<ENTRY> !  </ENTRY>
	<ENTRY>Factorial</ENTRY>
	<ENTRY>3 !</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> !!  </ENTRY>
	<ENTRY>Factorial (left operator)</ENTRY>
	<ENTRY>!! 3</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> % </ENTRY>
	<ENTRY>Modulo</ENTRY>
	<ENTRY>5 % 4</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> % </ENTRY>
	<ENTRY>Truncate</ENTRY>
	<ENTRY>% 4.5</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> * </ENTRY>
	<ENTRY>Multiplication</ENTRY>
	<ENTRY>2 * 3</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> + </ENTRY>
	<ENTRY>Addition</ENTRY>
	<ENTRY>2 + 3</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> - </ENTRY>
	<ENTRY>Subtraction</ENTRY>
	<ENTRY>2 - 3</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> / </ENTRY>
	<ENTRY>Division</ENTRY>
	<ENTRY>4 / 2</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> : </ENTRY>
	<ENTRY>Natural Exponentiation</ENTRY>
	<ENTRY>: 3.0</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> ; </ENTRY>
	<ENTRY>Natural Logarithm</ENTRY>
	<ENTRY>(; 5.0)</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> @ </ENTRY>
	<ENTRY>Absolute value</ENTRY>
	<ENTRY>@ -5.0</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> ^ </ENTRY>
	<ENTRY>Exponentiation</ENTRY>
	<ENTRY>2.0 ^ 3.0</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> |/ </ENTRY>
	<ENTRY>Square root</ENTRY>
	<ENTRY>|/ 25.0</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> ||/ </ENTRY>
	<ENTRY>Cube root</ENTRY>
	<ENTRY>||/ 27.0</ENTRY>
       </ROW>
      </TBODY>
     </TGROUP>
    </TABLE>
   </Para>

   <para>
    <note>
     <para>
      The operators ":" and ";" are deprecated, and will be removed in
      the near future.  Use the equivalent functions exp() and ln()
      instead.
     </para>
    </note>
   </para>

  </sect1>

  <sect1>
   <title>Geometric Operators</title>

   <Para>
    <TABLE TOCENTRY="1">
     <TITLE><ProductName>Postgres</ProductName> Geometric Operators</TITLE>
     <TITLEABBREV>Operators</TITLEABBREV>
     <TGROUP COLS="3">
      <THEAD>
       <ROW>
	<ENTRY>Operator</ENTRY>
	<ENTRY>Description</ENTRY>
	<ENTRY>Usage</ENTRY>
       </ROW>
      </THEAD>
      <TBODY>
       <ROW>
	<ENTRY> + </ENTRY>
	<ENTRY>Translation</ENTRY>
	<ENTRY>'((0,0),(1,1))'::box + '(2.0,0)'::point</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> - </ENTRY>
	<ENTRY>Translation</ENTRY>
	<ENTRY>'((0,0),(1,1))'::box - '(2.0,0)'::point</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> * </ENTRY>
	<ENTRY>Scaling/rotation</ENTRY>
	<ENTRY>'((0,0),(1,1))'::box * '(2.0,0)'::point</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> / </ENTRY>
	<ENTRY>Scaling/rotation</ENTRY>
	<ENTRY>'((0,0),(2,2))'::box / '(2.0,0)'::point</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> # </ENTRY>
	<ENTRY>Intersection</ENTRY>
	<ENTRY>'((1,-1),(-1,1))' # '((1,1),(-1,-1))'</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> # </ENTRY>
	<ENTRY>Number of points in polygon</ENTRY>
	<ENTRY># '((1,0),(0,1),(-1,0))'</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> ## </ENTRY>
	<ENTRY>Point of closest proximity</ENTRY>
	<ENTRY>'(0,0)'::point ## '((2,0),(0,2))'::lseg</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &amp;&amp; </ENTRY>
	<ENTRY>Overlaps?</ENTRY>
	<ENTRY>'((0,0),(1,1))'::box &amp;&amp; '((0,0),(2,2))'::box</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &amp;&lt; </ENTRY>
	<ENTRY>Overlaps to left?</ENTRY>
	<ENTRY>'((0,0),(1,1))'::box &amp;&lt; '((0,0),(2,2))'::box</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &amp;&gt; </ENTRY>
	<ENTRY>Overlaps to right?</ENTRY>
	<ENTRY>'((0,0),(3,3))'::box &amp;&gt; '((0,0),(2,2))'::box</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;-&gt; </ENTRY>
	<ENTRY>Distance between</ENTRY>
	<ENTRY>'((0,0),1)'::circle &lt;-&gt; '((5,0),1)'::circle</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;&lt; </ENTRY>
	<ENTRY>Left of?</ENTRY>
	<ENTRY>'((0,0),1)'::circle &lt;&lt; '((5,0),1)'::circle</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;^ </ENTRY>
	<ENTRY>Is below?</ENTRY>
	<ENTRY>'((0,0),1)'::circle &lt;^ '((0,5),1)'::circle</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &gt;&gt; </ENTRY>
	<ENTRY>Is right of?</ENTRY>
	<ENTRY>'((5,0),1)'::circle &gt;&gt; '((0,0),1)'::circle</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &gt;^ </ENTRY>
	<ENTRY>Is above?</ENTRY>
	<ENTRY>'((0,5),1)'::circle >^ '((0,0),1)'::circle</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> ?# </ENTRY>
	<ENTRY>Intersects or overlaps</ENTRY>
	<ENTRY>'((-1,0),(1,0))'::lseg ?# '((-2,-2),(2,2))'::box;</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> ?- </ENTRY>
	<ENTRY>Is horizontal?</ENTRY>
	<ENTRY>'(1,0)'::point ?- '(0,0)'::point</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> ?-| </ENTRY>
	<ENTRY>Is perpendicular?</ENTRY>
	<ENTRY>'((0,0),(0,1))'::lseg ?-| '((0,0),(1,0))'::lseg</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> @-@  </ENTRY>
	<ENTRY>Length or circumference</ENTRY>
	<ENTRY>@-@ '((0,0),(1,0))'::path</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> ?| </ENTRY>
	<ENTRY>Is vertical?</ENTRY>
	<ENTRY>'(0,1)'::point ?| '(0,0)'::point</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> ?|| </ENTRY>
	<ENTRY>Is parallel?</ENTRY>
	<ENTRY>'((-1,0),(1,0))'::lseg ?|| '((-1,2),(1,2))'::lseg</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> @ </ENTRY>
	<ENTRY>Contained or on</ENTRY>
	<ENTRY>'(1,1)'::point @ '((0,0),2)'::circle</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> @@ </ENTRY>
	<ENTRY>Center of</ENTRY>
	<ENTRY>@@ '((0,0),10)'::circle</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> ~= </ENTRY>
	<ENTRY>Same as</ENTRY>
	<ENTRY>'((0,0),(1,1))'::polygon ~= '((1,1),(0,0))'::polygon</ENTRY>
       </ROW>
      </TBODY>
     </TGROUP>
    </TABLE>
   </Para>
  </sect1>
  
  <sect1>
   <title>Time Interval Operators</title>
   
   <Para>
    The time interval data type <Type>tinterval</Type> is a legacy from the original
    date/time types and is not as well supported as the more modern types. There
    are several operators for this type.
    
    <TABLE TOCENTRY="1">
     <TITLE><ProductName>Postgres</ProductName> Time Interval Operators</TITLE>
     <TITLEABBREV>Operators</TITLEABBREV>
     <TGROUP COLS="3">
      <THEAD>
       <ROW>
	<ENTRY>Operator</ENTRY>
	<ENTRY>Description</ENTRY>
	<ENTRY>Usage</ENTRY>
       </ROW>
      </THEAD>
      <TBODY>
       <ROW>
	<ENTRY> #&lt; </ENTRY>
	<ENTRY>Interval less than?</ENTRY>
	<ENTRY></ENTRY>
       </ROW>
       <ROW>
	<ENTRY> #&lt;= </ENTRY>
	<ENTRY>Interval less than or equal to?</ENTRY>
	<ENTRY></ENTRY>
       </ROW>
       <ROW>
	<ENTRY> #&lt;&gt; </ENTRY>
	<ENTRY>Interval not equal?</ENTRY>
	<ENTRY></ENTRY>
       </ROW>
       <ROW>
	<ENTRY> #= </ENTRY>
	<ENTRY>Interval equal?</ENTRY>
	<ENTRY></ENTRY>
       </ROW>
       <ROW>
	<ENTRY> #&gt; </ENTRY>
	<ENTRY>Interval greater than?</ENTRY>
	<ENTRY></ENTRY>
       </ROW>
       <ROW>
	<ENTRY> #&gt;= </ENTRY>
	<ENTRY>Interval greater than or equal to?</ENTRY>
	<ENTRY></ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;#&gt; </ENTRY>
	<ENTRY>Convert to time interval</ENTRY>
	<ENTRY></ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;&lt; </ENTRY>
	<ENTRY>Interval less than?</ENTRY>
	<ENTRY></ENTRY>
       </ROW>
       <ROW>
	<ENTRY> | </ENTRY>
	<ENTRY>Start of interval</ENTRY>
	<ENTRY></ENTRY>
       </ROW>
       <ROW>
	<ENTRY> ~= </ENTRY>
	<ENTRY>Same as</ENTRY>
	<ENTRY></ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;?&gt; </ENTRY>
	<ENTRY>Time inside interval?</ENTRY>
	<ENTRY></ENTRY>
       </ROW>
      </TBODY>
     </TGROUP>
    </TABLE>
   </Para>
  </sect1>

  <Sect1>
   <title id="cidr-opers">IP V4 CIDR Operators</title>

   <Para>
    <TABLE TOCENTRY="1">
     <TITLE><ProductName>Postgres</ProductName>IP V4 CIDR Operators</TITLE>
     <TITLEABBREV>Operators</TITLEABBREV>
     <TGROUP COLS="3">
      <THEAD>
       <ROW>
	<ENTRY>Operator</ENTRY>
	<ENTRY>Description</ENTRY>
	<ENTRY>Usage</ENTRY>
       </ROW>
      </THEAD>
      <TBODY>
       <ROW>
	<ENTRY> &lt; </ENTRY>
	<ENTRY>Less than</ENTRY>
	<ENTRY>'192.168.1.5'::cidr &lt; '192.168.1.6'::cidr</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;= </ENTRY>
	<ENTRY>Less than or equal</ENTRY>
	<ENTRY>'192.168.1.5'::cidr &lt;= '192.168.1.5'::cidr</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> = </ENTRY>
	<ENTRY>Equals</ENTRY>
	<ENTRY>'192.168.1.5'::cidr = '192.168.1.5'::cidr</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &gt;= </ENTRY>
	<ENTRY>Greater or equal</ENTRY>
	<ENTRY>'192.168.1.5'::cidr &gt;= '192.168.1.5'::cidr</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &gt; </ENTRY>
	<ENTRY>Greater</ENTRY>
	<ENTRY>'192.168.1.5'::cidr &gt; '192.168.1.4'::cidr</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;&gt; </ENTRY>
	<ENTRY>Not equal</ENTRY>
	<ENTRY>'192.168.1.5'::cidr &lt;&gt; '192.168.1.4'::cidr</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;&lt; </ENTRY>
	<ENTRY>is contained within</ENTRY>
	<ENTRY>'192.168.1.5'::cidr &lt;&lt; '192.168.1/24'::cidr</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;&lt;= </ENTRY>
	<ENTRY>is contained within or equals</ENTRY>
	<ENTRY>'192.168.1/24'::cidr &lt;&lt;= '192.168.1/24'::cidr</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &gt;&gt; </ENTRY>
	<ENTRY>contains</ENTRY>
	<ENTRY>'192.168.1/24'::cidr &gt;&gt; '192.168.1.5'::cidr</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &gt;&gt;= </ENTRY>
	<ENTRY>contains or equals</ENTRY>
	<ENTRY>'192.168.1/24'::cidr &gt;&gt;= '192.168.1/24'::cidr</ENTRY>
       </ROW>
      </TBODY>
     </TGROUP>
    </TABLE>
   </Para>
  </Sect1>

  <Sect1>
   <title id="inet-opers">IP V4 INET Operators</title>
   
   <Para>
    <TABLE TOCENTRY="1">
     <TITLE><ProductName>Postgres</ProductName>IP V4 INET Operators</TITLE>
     <TITLEABBREV>Operators</TITLEABBREV>
     <TGROUP COLS="3">
      <THEAD>
       <ROW>
	<ENTRY>Operator</ENTRY>
	<ENTRY>Description</ENTRY>
	<ENTRY>Usage</ENTRY>
       </ROW>
      </THEAD>
      <TBODY>
       <ROW>
	<ENTRY> &lt; </ENTRY>
	<ENTRY>Less than</ENTRY>
	<ENTRY>'192.168.1.5'::inet &lt; '192.168.1.6'::inet</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;= </ENTRY>
	<ENTRY>Less than or equal</ENTRY>
	<ENTRY>'192.168.1.5'::inet &lt;= '192.168.1.5'::inet</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> = </ENTRY>
	<ENTRY>Equals</ENTRY>
	<ENTRY>'192.168.1.5'::inet = '192.168.1.5'::inet</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &gt;= </ENTRY>
	<ENTRY>Greater or equal</ENTRY>
	<ENTRY>'192.168.1.5'::inet &gt;= '192.168.1.5'::inet</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &gt; </ENTRY>
	<ENTRY>Greater</ENTRY>
	<ENTRY>'192.168.1.5'::inet &gt; '192.168.1.4'::inet</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;&gt; </ENTRY>
	<ENTRY>Not equal</ENTRY>
	<ENTRY>'192.168.1.5'::inet &lt;&gt; '192.168.1.4'::inet</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;&lt; </ENTRY>
	<ENTRY>is contained within</ENTRY>
	<ENTRY>'192.168.1.5'::inet &lt;&lt; '192.168.1/24'::inet</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &lt;&lt;= </ENTRY>
	<ENTRY>is contained within or equals</ENTRY>
	<ENTRY>'192.168.1/24'::inet &lt;&lt;= '192.168.1/24'::inet</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &gt;&gt; </ENTRY>
	<ENTRY>contains</ENTRY>
	<ENTRY>'192.168.1/24'::inet &gt;&gt; '192.168.1.5'::inet</ENTRY>
       </ROW>
       <ROW>
	<ENTRY> &gt;&gt;= </ENTRY>
	<ENTRY>contains or equals</ENTRY>
	<ENTRY>'192.168.1/24'::inet &gt;&gt;= '192.168.1/24'::inet</ENTRY>
       </ROW>
      </TBODY>
     </TGROUP>
    </TABLE>
   </Para>
  </Sect1>

 </Chapter>

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