Document which aggregates support partial mode.

David Rowley, reviewed by Tomas Vondra

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 9b0778baa9978eb20b2d5fbe638871a756e7464d..396eaa5d550035163a98d776c043d4b6d278a449 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -12678,12 +12678,13 @@ NULL baz(3 rows)
   
    General-Purpose Aggregate Functions
 
-   4">
+   5">
     
      
       Function
       Argument Type(s)
       Return Type
+      Partial Mode
       Description
      
     
@@ -12702,6 +12703,7 @@ NULL baz(3 rows)
       
        array of the argument type
       
+      No
       input values, including nulls, concatenated into an array
      
 
@@ -12715,6 +12717,7 @@ NULL baz(3 rows)
       
        same as argument data type
       
+      No
       input arrays concatenated into array of one higher dimension
        (inputs must all have same dimensionality,
         and cannot be empty or NULL)
@@ -12740,6 +12743,7 @@ NULL baz(3 rows)
        double precision for a floating-point argument,
        otherwise the same as the argument data type
       
+      All types apart from floating-point types
       the average (arithmetic mean) of all input values
      
 
@@ -12757,6 +12761,7 @@ NULL baz(3 rows)
       
         same as argument data type
       
+      Yes
       the bitwise AND of all non-null input values, or null if none
      
 
@@ -12774,6 +12779,7 @@ NULL baz(3 rows)
       
         same as argument data type
       
+      Yes
       the bitwise OR of all non-null input values, or null if none
      
 
@@ -12790,6 +12796,7 @@ NULL baz(3 rows)
       
        bool
       
+      Yes
       true if all input values are true, otherwise false
      
 
@@ -12806,6 +12813,7 @@ NULL baz(3 rows)
       
        bool
       
+      Yes
       true if at least one input value is true, otherwise false
      
 
@@ -12818,6 +12826,7 @@ NULL baz(3 rows)
       
       
       bigint
+      Yes
       number of input rows
      
 
@@ -12825,6 +12834,7 @@ NULL baz(3 rows)
       count(expression)
       any
       bigint
+      Yes
       
        number of input rows for which the value of 
        class="parameter">expression is not null
@@ -12844,6 +12854,7 @@ NULL baz(3 rows)
       
        bool
       
+      Yes
       equivalent to bool_and
      
 
@@ -12860,6 +12871,7 @@ NULL baz(3 rows)
       
        json
       
+      No
       aggregates values as a JSON array
      
 
@@ -12876,6 +12888,7 @@ NULL baz(3 rows)
       
        jsonb
       
+      No
       aggregates values as a JSON array
      
 
@@ -12892,6 +12905,7 @@ NULL baz(3 rows)
       
        json
       
+      No
       aggregates name/value pairs as a JSON object
      
 
@@ -12908,6 +12922,7 @@ NULL baz(3 rows)
       
        jsonb
       
+      No
       aggregates name/value pairs as a JSON object
      
 
@@ -12921,6 +12936,7 @@ NULL baz(3 rows)
       any numeric, string, date/time, network, or enum type,
              or arrays of these types
       same as argument type
+      Yes
       
        maximum value of 
        class="parameter">expression across all input
@@ -12938,6 +12954,7 @@ NULL baz(3 rows)
       any numeric, string, date/time, network, or enum type,
              or arrays of these types
       same as argument type
+      Yes
       
        minimum value of 
        class="parameter">expression across all input
@@ -12961,6 +12978,7 @@ NULL baz(3 rows)
       
        same as argument types
       
+      No
       input values concatenated into a string, separated by delimiter
      
 
@@ -12983,6 +13001,7 @@ NULL baz(3 rows)
        bigint arguments, otherwise the same as the
        argument data type
       
+      All types apart from floating-point types
       sum of expression across all input values
      
 
@@ -12999,6 +13018,7 @@ NULL baz(3 rows)
       
        xml
       
+      No
       concatenation of XML values (see also )
      
     
@@ -13015,6 +13035,12 @@ NULL baz(3 rows)
    substitute zero or an empty array for null when necessary.
   
 
+  
+   Aggregate functions which support Partial Mode
+   are eligible to participate in various optimizations, such as parallel
+   aggregation.
+  
+
   
     
       ANY
@@ -13098,12 +13124,13 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
   
    Aggregate Functions for Statistics
 
-   4">
+   5">
     
      
       Function
       Argument Type
       Return Type
+      Partial Mode
       Description
      
     
@@ -13126,6 +13153,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        double precision
       
+      No
       correlation coefficient
      
 
@@ -13146,6 +13174,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        double precision
       
+      No
       population covariance
      
 
@@ -13166,6 +13195,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        double precision
       
+      No
       sample covariance
      
 
@@ -13182,6 +13212,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        double precision
       
+      No
       average of the independent variable
       (sum(X)/N)
      
@@ -13199,6 +13230,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        double precision
       
+      No
       average of the dependent variable
       (sum(Y)/N)
      
@@ -13216,6 +13248,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        bigint
       
+      No
       number of input rows in which both expressions are nonnull
      
 
@@ -13235,6 +13268,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        double precision
       
+      No
       y-intercept of the least-squares-fit linear equation
       determined by the (
       class="parameter">X, 
@@ -13254,6 +13288,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        double precision
       
+      No
       square of the correlation coefficient
      
 
@@ -13273,6 +13308,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        double precision
       
+      No
       slope of the least-squares-fit linear equation determined
       by the (X,
       Y) pairs
@@ -13291,6 +13327,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        double precision
       
+      No
       sum(
       class="parameter">X^2) - sum(
       class="parameter">X)^2/
@@ -13311,6 +13348,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        double precision
       
+      No
       sum(
       class="parameter">X*
       class="parameter">Y) - sum(
@@ -13334,6 +13372,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        double precision
       
+      No
       sum(
       class="parameter">Y^2) - sum(
       class="parameter">Y)^2/
@@ -13360,6 +13399,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
        double precision for floating-point arguments,
        otherwise numeric
       
+      All types apart from floating-point types
       historical alias for stddev_samp
      
 
@@ -13383,6 +13423,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
        double precision for floating-point arguments,
        otherwise numeric
       
+      All types apart from floating-point types
       population standard deviation of the input values
      
 
@@ -13406,6 +13447,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
        double precision for floating-point arguments,
        otherwise numeric
       
+      All types apart from floating-point types
       sample standard deviation of the input values
      
 
@@ -13425,6 +13467,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
        double precision for floating-point arguments,
        otherwise numeric
       
+      All types apart from floating-point types
       historical alias for var_samp
      
 
@@ -13448,6 +13491,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
        double precision for floating-point arguments,
        otherwise numeric
       
+      All types apart from floating-point types
       population variance of the input values (square of the population standard deviation)
      
 
@@ -13471,6 +13515,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
        double precision for floating-point arguments,
        otherwise numeric
       
+      All types apart from floating-point types
       sample variance of the input values (square of the sample standard deviation)
      
     
@@ -13495,13 +13540,14 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
   
    Ordered-Set Aggregate Functions
 
-   5">
+   6">
     
      
       Function
       Direct Argument Type(s)
       Aggregated Argument Type(s)
       Return Type
+      Partial Mode
       Description
      
     
@@ -13524,6 +13570,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        same as sort expression
       
+      No
       
        returns the most frequent input value (arbitrarily choosing the first
        one if there are multiple equally-frequent results)
@@ -13550,6 +13597,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        same as sort expression
       
+      No
       
        continuous percentile: returns a value corresponding to the specified
        fraction in the ordering, interpolating between adjacent input items if
@@ -13570,6 +13618,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        array of sort expression's type
       
+      No
       
        multiple continuous percentile: returns an array of results matching
        the shape of the fractions parameter, with each
@@ -13594,6 +13643,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        same as sort expression
       
+      No
       
        discrete percentile: returns the first input value whose position in
        the ordering equals or exceeds the specified fraction
@@ -13613,6 +13663,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        array of sort expression's type
       
+      No
       
        multiple discrete percentile: returns an array of results matching the
        shape of the fractions parameter, with each non-null
@@ -13651,13 +13702,14 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
   
    Hypothetical-Set Aggregate Functions
 
-   5">
+   6">
     
      
       Function
       Direct Argument Type(s)
       Aggregated Argument Type(s)
       Return Type
+      Partial Mode
       Description
      
     
@@ -13681,6 +13733,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        bigint
       
+      No
       
        rank of the hypothetical row, with gaps for duplicate rows
       
@@ -13703,6 +13756,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        bigint
       
+      No
       
        rank of the hypothetical row, without gaps
       
@@ -13725,6 +13779,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        double precision
       
+      No
       
        relative rank of the hypothetical row, ranging from 0 to 1
       
@@ -13747,6 +13802,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       
        double precision
       
+      No
       
        relative rank of the hypothetical row, ranging from
        1/N to 1




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