Document a bunch of formerly-undocumented date/time operators,

including the SQL-spec OVERLAPS construct.

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 62f8ff6fd73a3d2701c16de012953399144e0ae9..e53a9c2a943f5f97281f209528b19e6520087a46 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1,5 +1,5 @@
 
 
@@ -4575,8 +4575,8 @@ substring('foobar' from 'o(.)b')   o
       
        
          + 
-        timestamp '2001-09-28 01:00' + interval '23 hours'
-        timestamp '2001-09-29 00:00'
+        date '2001-09-28' + integer '7'
+        date '2001-10-05'
        
 
        
@@ -4585,16 +4585,58 @@ substring('foobar' from 'o(.)b')   o
         timestamp '2001-09-28 01:00'
        
 
+       
+         + 
+        date '2001-09-28' + time '03:00'
+        timestamp '2001-09-28 03:00'
+       
+
+       
+         + 
+        time '03:00' + date '2001-09-28'
+        timestamp '2001-09-28 03:00'
+       
+
+       
+         + 
+        interval '1 day' + interval '1 hour'
+        interval '1 day 01:00'
+       
+
+       
+         + 
+        timestamp '2001-09-28 01:00' + interval '23 hours'
+        timestamp '2001-09-29 00:00'
+       
+
        
          + 
         time '01:00' + interval '3 hours'
         time '04:00'
        
 
+       
+         + 
+        interval '3 hours' + time '01:00'
+        time '04:00'
+       
+
        
          - 
-        timestamp '2001-09-28 23:00' - interval '23 hours'
-        timestamp '2001-09-28'
+        - interval '23 hours'
+        interval '-23:00'
+       
+
+       
+         - 
+        date '2001-10-01' - date '2001-09-28'
+        integer '3'
+       
+
+       
+         - 
+        date '2001-10-01' - integer '7'
+        date '2001-09-24'
        
 
        
@@ -4603,28 +4645,58 @@ substring('foobar' from 'o(.)b')   o
         timestamp '2001-09-27 23:00'
        
 
+       
+         - 
+        time '05:00' - time '03:00'
+        interval '02:00'
+       
+
        
          - 
         time '05:00' - interval '2 hours'
         time '03:00'
        
 
+       
+         - 
+        timestamp '2001-09-28 23:00' - interval '23 hours'
+        timestamp '2001-09-28 00:00'
+       
+
+       
+         - 
+        interval '1 day' - interval '1 hour'
+        interval '23:00'
+       
+
        
          - 
         interval '2 hours' - time '05:00'
-        time '03:00:00'
+        time '03:00'
+       
+
+       
+         - 
+        timestamp '2001-09-29 03:00' - timestamp '2001-09-27 12:00'
+        interval '1 day 15:00'
+       
+
+       
+         * 
+        double precision '3.5' * interval '1 hour'
+        interval '03:30'
        
 
        
          * 
-        interval '1 hour' * int '3'
-        interval '03:00'
+        interval '1 hour' * double precision '3.5'
+        interval '03:30'
        
 
        
          / 
-        interval '1 hour' / int '3'
-        interval '00:20'
+        interval '1 hour' / double precision '1.5'
+        interval '00:40'
        
       
      
@@ -4714,7 +4786,7 @@ substring('foobar' from 'o(.)b')   o
                                                         linkend="functions-datetime-trunc">
         
    date_trunc('hour', timestamp '2001-02-16 20:38:40')
-   2001-02-16 20:00:00+00
+   2001-02-16 20:00:00
        
 
        
@@ -4788,14 +4860,36 @@ substring('foobar' from 'o(.)b')   o
    Current date and time; see 
                                          linkend="functions-datetime-current">
    
-   <literal>timeofday()</entry>
-   <literal>Wed Feb 21 17:01:13.000126 2001 EST</entry>
+   
+   
        
 
       
      
     
 
+   
+    In addition to these functions, the SQL OVERLAPS keyword is
+    supported:
+
+( start1, end1 ) OVERLAPS ( start2, end2 )
+( start1, length1 ) OVERLAPS ( start2, length2 )
+
+    This expression yields true when two time periods (defined by their
+    endpoints) overlap, false when they do not overlap.  The endpoints
+    can be specified as pairs of dates, times, or timestamps; or as
+    a date, time, or timestamp followed by an interval.
+   
+
+
+SELECT (DATE '2001-02-16', DATE '2001-12-21') OVERLAPS
+       (DATE '2001-10-30', DATE '2002-10-30');
+Result: true
+SELECT (DATE '2001-02-16', INTERVAL '100 days') OVERLAPS
+       (DATE '2001-10-30', DATE '2002-10-30');
+Result: false
+
+
   
    <function>EXTRACT</function>, <function>date_part</function>
 
@@ -4906,8 +5000,8 @@ SELECT EXTRACT(DOY FROM TIMESTAMP '2001-02-16 20:38:40');
        
 
 
-SELECT EXTRACT(EPOCH FROM TIMESTAMP '2001-02-16 20:38:40');
-Result: 982352320
+SELECT EXTRACT(EPOCH FROM TIMESTAMP WITH TIME ZONE '2001-02-16 20:38:40-08');
+Result: 982384720
 
 SELECT EXTRACT(EPOCH FROM INTERVAL '5 days 3 hours');
 Result: 442800
@@ -5156,11 +5250,14 @@ SELECT date_part('hour', INTERVAL '4 hours 3 minutes');
 date_trunc('field', source)
 
     source is a value expression of type
-    timestamp.  (Values of type date and
-    time are cast automatically.)
+    timestamp or interval.
+    (Values of type date and
+    time are cast automatically, to timestamp or
+    interval respectively.)
     field selects to which precision to
-    truncate the time stamp value.  The return value is of type
-    timestamp with all fields that are less than the
+    truncate the input value.  The return value is of type
+    timestamp or interval
+    with all fields that are less significant than the
     selected one set to zero (or one, for day and month).
    
 
@@ -5185,10 +5282,10 @@ date_trunc('field', source
     Examples:
 
 SELECT date_trunc('hour', TIMESTAMP '2001-02-16 20:38:40');
-Result: 2001-02-16 20:00:00+00
+Result: 2001-02-16 20:00:00
 
 SELECT date_trunc('year', TIMESTAMP '2001-02-16 20:38:40');
-Result: 2001-01-01 00:00:00+00
+Result: 2001-01-01 00:00:00