Merge pull request #865 from katzyn/filter

Add optional FILTER to aggregates

h2/src/docsrc/help/help.csv

@@ -2636,7 +2636,7 @@ GEOMETRY
 "
 
 "Functions (Aggregate)","AVG","
-AVG ( [ DISTINCT ] { numeric } )
+AVG ( [ DISTINCT ] { numeric } ) [ FILTER ( WHERE expression ) ]
 ","
 The average (mean) value.
 If no rows are selected, the result is NULL.
@@ -2647,7 +2647,7 @@ AVG(X)
 "
 
 "Functions (Aggregate)","BIT_AND","
-BIT_AND(expression)
+BIT_AND(expression) [ FILTER ( WHERE expression ) ]
 ","
 The bitwise AND of all non-null values.
 If no rows are selected, the result is NULL.
@@ -2657,7 +2657,7 @@ BIT_AND(ID)
 "
 
 "Functions (Aggregate)","BIT_OR","
-BIT_OR(expression)
+BIT_OR(expression) [ FILTER ( WHERE expression ) ]
 ","
 The bitwise OR of all non-null values.
 If no rows are selected, the result is NULL.
@@ -2667,7 +2667,7 @@ BIT_OR(ID)
 "
 
 "Functions (Aggregate)","BOOL_AND","
-BOOL_AND(boolean)
+BOOL_AND(boolean) [ FILTER ( WHERE expression ) ]
 ","
 Returns true if all expressions are true.
 If no rows are selected, the result is NULL.
@@ -2677,7 +2677,7 @@ BOOL_AND(ID>10)
 "
 
 "Functions (Aggregate)","BOOL_OR","
-BOOL_OR(boolean)
+BOOL_OR(boolean) [ FILTER ( WHERE expression ) ]
 ","
 Returns true if any expression is true.
 If no rows are selected, the result is NULL.
@@ -2687,7 +2687,7 @@ BOOL_OR(NAME LIKE 'W%')
 "
 
 "Functions (Aggregate)","COUNT","
-COUNT( { * | { [ DISTINCT ] expression } } )
+COUNT( { * | { [ DISTINCT ] expression } } ) [ FILTER ( WHERE expression ) ]
 ","
 The count of all row, or of the non-null values.
 This method returns a long.
@@ -2700,7 +2700,7 @@ COUNT(*)
 "Functions (Aggregate)","GROUP_CONCAT","
 GROUP_CONCAT ( [ DISTINCT ] string
 [ ORDER BY { expression [ ASC | DESC ] } [,...] ]
-[ SEPARATOR expression ] )
+[ SEPARATOR expression ] ) [ FILTER ( WHERE expression ) ]
 ","
 Concatenates strings with a separator.
 The default separator is a ',' (without space).
@@ -2712,7 +2712,7 @@ GROUP_CONCAT(NAME ORDER BY ID SEPARATOR ', ')
 "
 
 "Functions (Aggregate)","MAX","
-MAX(value)
+MAX(value) [ FILTER ( WHERE expression ) ]
 ","
 The highest value.
 If no rows are selected, the result is NULL.
@@ -2723,7 +2723,7 @@ MAX(NAME)
 "
 
 "Functions (Aggregate)","MIN","
-MIN(value)
+MIN(value) [ FILTER ( WHERE expression ) ]
 ","
 The lowest value.
 If no rows are selected, the result is NULL.
@@ -2734,7 +2734,7 @@ MIN(NAME)
 "
 
 "Functions (Aggregate)","SUM","
-SUM( [ DISTINCT ] { numeric } )
+SUM( [ DISTINCT ] { numeric } ) [ FILTER ( WHERE expression ) ]
 ","
 The sum of all values.
 If no rows are selected, the result is NULL.
@@ -2746,7 +2746,7 @@ SUM(X)
 "
 
 "Functions (Aggregate)","SELECTIVITY","
-SELECTIVITY(value)
+SELECTIVITY(value) [ FILTER ( WHERE expression ) ]
 ","
 Estimates the selectivity (0-100) of a value.
 The value is defined as (100 * distinctCount / rowCount).
@@ -2758,7 +2758,7 @@ SELECT SELECTIVITY(FIRSTNAME), SELECTIVITY(NAME) FROM TEST WHERE ROWNUM()<20000
 "
 
 "Functions (Aggregate)","STDDEV_POP","
-STDDEV_POP( [ DISTINCT ] numeric )
+STDDEV_POP( [ DISTINCT ] numeric ) [ FILTER ( WHERE expression ) ]
 ","
 The population standard deviation.
 This method returns a double.
@@ -2769,7 +2769,7 @@ STDDEV_POP(X)
 "
 
 "Functions (Aggregate)","STDDEV_SAMP","
-STDDEV_SAMP( [ DISTINCT ] numeric )
+STDDEV_SAMP( [ DISTINCT ] numeric ) [ FILTER ( WHERE expression ) ]
 ","
 The sample standard deviation.
 This method returns a double.
@@ -2780,7 +2780,7 @@ STDDEV(X)
 "
 
 "Functions (Aggregate)","VAR_POP","
-VAR_POP( [ DISTINCT ] numeric )
+VAR_POP( [ DISTINCT ] numeric ) [ FILTER ( WHERE expression ) ]
 ","
 The population variance (square of the population standard deviation).
 This method returns a double.
@@ -2791,7 +2791,7 @@ VAR_POP(X)
 "
 
 "Functions (Aggregate)","VAR_SAMP","
-VAR_SAMP( [ DISTINCT ] numeric )
+VAR_SAMP( [ DISTINCT ] numeric ) [ FILTER ( WHERE expression ) ]
 ","
 The sample variance (square of the sample standard deviation).
 This method returns a double.
@@ -2802,7 +2802,7 @@ VAR_SAMP(X)
 "
 
 "Functions (Aggregate)","MEDIAN","
-MEDIAN( [ DISTINCT ] value )
+MEDIAN( [ DISTINCT ] value ) [ FILTER ( WHERE expression ) ]
 ","
 The value separating the higher half of a values from the lower half.
 Returns the middle value or an interpolated value between two middle values if number of values is even.

h2/src/main/org/h2/command/Parser.java

@@ -2627,7 +2627,7 @@ public class Parser {
             throw getSyntaxError();
         }
         currentSelect.setGroupQuery();
-        Expression r;
+        Aggregate r;
         if (aggregateType == AggregateType.COUNT) {
             if (readIf("*")) {
                 r = new Aggregate(AggregateType.COUNT_ALL, null, currentSelect,
@@ -2645,38 +2645,45 @@ public class Parser {
                 }
             }
         } else if (aggregateType == AggregateType.GROUP_CONCAT) {
-            Aggregate agg = null;
             boolean distinct = readIf("DISTINCT");
 
             if (equalsToken("GROUP_CONCAT", aggregateName)) {
-                agg = new Aggregate(AggregateType.GROUP_CONCAT,
+                r = new Aggregate(AggregateType.GROUP_CONCAT,
                     readExpression(), currentSelect, distinct);
                 if (readIf("ORDER")) {
                     read("BY");
-                    agg.setGroupConcatOrder(parseSimpleOrderList());
+                    r.setGroupConcatOrder(parseSimpleOrderList());
                 }
 
                 if (readIf("SEPARATOR")) {
-                    agg.setGroupConcatSeparator(readExpression());
+                    r.setGroupConcatSeparator(readExpression());
                 }
             } else if (equalsToken("STRING_AGG", aggregateName)) {
                 // PostgreSQL compatibility: string_agg(expression, delimiter)
-                agg = new Aggregate(AggregateType.GROUP_CONCAT,
+                r = new Aggregate(AggregateType.GROUP_CONCAT,
                     readExpression(), currentSelect, distinct);
                 read(",");
-                agg.setGroupConcatSeparator(readExpression());
+                r.setGroupConcatSeparator(readExpression());
                 if (readIf("ORDER")) {
                     read("BY");
-                    agg.setGroupConcatOrder(parseSimpleOrderList());
+                    r.setGroupConcatOrder(parseSimpleOrderList());
                 }
+            } else {
+                r = null;
             }
-            r = agg;
         } else {
             boolean distinct = readIf("DISTINCT");
             r = new Aggregate(aggregateType, readExpression(), currentSelect,
                     distinct);
         }
         read(")");
+        if (r != null && readIf("FILTER")) {
+            read("(");
+            read("WHERE");
+            Expression condition = readExpression();
+            read(")");
+            r.setFilterCondition(condition);
+        }
         return r;
     }
 
@@ -2727,8 +2734,17 @@ public class Parser {
             params.add(readExpression());
         } while (readIf(","));
         read(")");
+        Expression filterCondition;
+        if (readIf("FILTER")) {
+            read("(");
+            read("WHERE");
+            filterCondition = readExpression();
+            read(")");
+        } else {
+            filterCondition = null;
+        }
         Expression[] list = params.toArray(new Expression[0]);
-        JavaAggregate agg = new JavaAggregate(aggregate, list, currentSelect);
+        JavaAggregate agg = new JavaAggregate(aggregate, list, currentSelect, filterCondition);
         currentSelect.setGroupQuery();
         return agg;
     }

h2/src/main/org/h2/expression/Aggregate.java

@@ -146,6 +146,8 @@ public class Aggregate extends Expression {
     private int displaySize;
     private int lastGroupRowId;
 
+    private Expression filterCondition;
+
     /**
      * Create a new aggregate object.
      *
@@ -228,6 +230,15 @@ public class Aggregate extends Expression {
         this.groupConcatSeparator = separator;
     }
 
+    /**
+     * Sets the FILTER condition.
+     *
+     * @param filterCondition condition
+     */
+    public void setFilterCondition(Expression filterCondition) {
+        this.filterCondition = filterCondition;
+    }
+
     private SortOrder initOrder(Session session) {
         int size = groupConcatOrderList.size();
         int[] index = new int[size];
@@ -281,6 +292,11 @@ public class Aggregate extends Expression {
                 }
             }
         }
+        if (filterCondition != null) {
+            if (!filterCondition.getBooleanValue(session)) {
+                return;
+            }
+        }
         data.add(session.getDatabase(), dataType, distinct, v);
     }
 
@@ -383,6 +399,9 @@ public class Aggregate extends Expression {
         if (groupConcatSeparator != null) {
             groupConcatSeparator.mapColumns(resolver, level);
         }
+        if (filterCondition != null) {
+            filterCondition.mapColumns(resolver, level);
+        }
     }
 
     @Override
@@ -403,6 +422,9 @@ public class Aggregate extends Expression {
         if (groupConcatSeparator != null) {
             groupConcatSeparator = groupConcatSeparator.optimize(session);
         }
+        if (filterCondition != null) {
+            filterCondition = filterCondition.optimize(session);
+        }
         switch (type) {
         case GROUP_CONCAT:
             dataType = Value.STRING;
@@ -487,6 +509,9 @@ public class Aggregate extends Expression {
         if (groupConcatSeparator != null) {
             groupConcatSeparator.setEvaluatable(tableFilter, b);
         }
+        if (filterCondition != null) {
+            filterCondition.setEvaluatable(tableFilter, b);
+        }
     }
 
     @Override
@@ -523,7 +548,11 @@ public class Aggregate extends Expression {
         if (groupConcatSeparator != null) {
             buff.append(" SEPARATOR ").append(groupConcatSeparator.getSQL());
         }
-        return buff.append(')').toString();
+        buff.append(')');
+        if (filterCondition != null) {
+            buff.append(" FILTER (WHERE ").append(filterCondition.getSQL()).append(')');
+        }
+        return buff.toString();
     }
 
     @Override
@@ -586,9 +615,14 @@ public class Aggregate extends Expression {
             throw DbException.throwInternalError("type=" + type);
         }
         if (distinct) {
-            return text + "(DISTINCT " + on.getSQL() + ")";
+            text += "(DISTINCT " + on.getSQL() + ')';
+        } else {
+            text += StringUtils.enclose(on.getSQL());
         }
-        return text + StringUtils.enclose(on.getSQL());
+        if (filterCondition != null) {
+            text += " FILTER (WHERE " + filterCondition.getSQL() + ')';
+        }
+        return text;
     }
 
     private Index getMinMaxColumnIndex() {
@@ -607,6 +641,9 @@ public class Aggregate extends Expression {
 
     @Override
     public boolean isEverything(ExpressionVisitor visitor) {
+        if (filterCondition != null && !filterCondition.isEverything(visitor)) {
+            return false;
+        }
         if (visitor.getType() == ExpressionVisitor.OPTIMIZABLE_MIN_MAX_COUNT_ALL) {
             switch (type) {
             case COUNT:
@@ -649,7 +686,14 @@ public class Aggregate extends Expression {
 
     @Override
     public int getCost() {
-        return (on == null) ? 1 : on.getCost() + 1;
+        int cost = 1;
+        if (on != null) {
+            cost += on.getCost();
+        }
+        if (filterCondition != null) {
+            cost += filterCondition.getCost();
+        }
+        return cost;
     }
 
 }

h2/src/main/org/h2/expression/JavaAggregate.java

@@ -31,15 +31,17 @@ public class JavaAggregate extends Expression {
     private final Select select;
     private final Expression[] args;
     private int[] argTypes;
+    private Expression filterCondition;
     private int dataType;
     private Connection userConnection;
     private int lastGroupRowId;
 
     public JavaAggregate(UserAggregate userAggregate, Expression[] args,
-            Select select) {
+            Select select, Expression filterCondition) {
         this.userAggregate = userAggregate;
         this.args = args;
         this.select = select;
+        this.filterCondition = filterCondition;
     }
 
     @Override
@@ -48,6 +50,9 @@ public class JavaAggregate extends Expression {
         for (Expression e : args) {
             cost += e.getCost();
         }
+        if (filterCondition != null) {
+            cost += filterCondition.getCost();
+        }
         return cost;
     }
 
@@ -74,7 +79,11 @@ public class JavaAggregate extends Expression {
             buff.appendExceptFirst(", ");
             buff.append(e.getSQL());
         }
-        return buff.append(')').toString();
+        buff.append(')');
+        if (filterCondition != null) {
+            buff.append(" FILTER (WHERE ").append(filterCondition.getSQL()).append(')');
+        }
+        return buff.toString();
     }
 
     @Override
@@ -101,6 +110,9 @@ public class JavaAggregate extends Expression {
                 return false;
             }
         }
+        if (filterCondition != null && !filterCondition.isEverything(visitor)) {
+            return false;
+        }
         return true;
     }
 
@@ -109,6 +121,9 @@ public class JavaAggregate extends Expression {
         for (Expression arg : args) {
             arg.mapColumns(resolver, level);
         }
+        if (filterCondition != null) {
+            filterCondition.mapColumns(resolver, level);
+        }
     }
 
     @Override
@@ -128,6 +143,9 @@ public class JavaAggregate extends Expression {
         } catch (SQLException e) {
             throw DbException.convert(e);
         }
+        if (filterCondition != null) {
+            filterCondition = filterCondition.optimize(session);
+        }
         return this;
     }
 
@@ -136,6 +154,9 @@ public class JavaAggregate extends Expression {
         for (Expression e : args) {
             e.setEvaluatable(tableFilter, b);
         }
+        if (filterCondition != null) {
+            filterCondition.setEvaluatable(tableFilter, b);
+        }
     }
 
     private Aggregate getInstance() throws SQLException {
@@ -180,6 +201,12 @@ public class JavaAggregate extends Expression {
         }
         lastGroupRowId = groupRowId;
 
+        if (filterCondition != null) {
+            if (!filterCondition.getBooleanValue(session)) {
+                return;
+            }
+        }
+
         Aggregate agg = (Aggregate) group.get(this);
         try {
             if (agg == null) {

h2/src/test/org/h2/test/db/TestFunctions.java

@@ -747,6 +747,10 @@ public class TestFunctions extends TestBase implements AggregateFunction {
                 "SELECT SIMPLE_MEDIAN(X) FROM SYSTEM_RANGE(1, 9)");
         rs.next();
         assertEquals("5", rs.getString(1));
+        rs = stat.executeQuery(
+                "SELECT SIMPLE_MEDIAN(X) FILTER (WHERE X > 2) FROM SYSTEM_RANGE(1, 9)");
+        rs.next();
+        assertEquals("6", rs.getString(1));
         conn.close();
 
         if (config.memory) {

h2/src/test/org/h2/test/scripts/functions/aggregate/avg.sql

@@ -2,3 +2,28 @@
 -- and the EPL 1.0 (http://h2database.com/html/license.html).
 -- Initial Developer: H2 Group
 --
+
+-- with filter condition
+
+create table test(v int);
+> ok
+
+insert into test values (10), (20), (30), (40), (50), (60), (70), (80), (90), (100), (110), (120);
+> update count: 12
+
+select avg(v), avg(v) filter (where v >= 40) from test where v <= 100;
+> AVG(V) AVG(V) FILTER (WHERE (V >= 40))
+> ------ -------------------------------
+> 55     70
+> rows: 1
+
+create index test_idx on test(v);
+
+select avg(v), avg(v) filter (where v >= 40) from test where v <= 100;
+> AVG(V) AVG(V) FILTER (WHERE (V >= 40))
+> ------ -------------------------------
+> 55     70
+> rows: 1
+
+drop table test;
+> ok

h2/src/test/org/h2/test/scripts/functions/aggregate/bit-and.sql

@@ -2,3 +2,31 @@
 -- and the EPL 1.0 (http://h2database.com/html/license.html).
 -- Initial Developer: H2 Group
 --
+
+-- with filter condition
+
+create table test(v bigint);
+> ok
+
+insert into test values
+    (0xfffffffffff0), (0xffffffffff0f), (0xfffffffff0ff), (0xffffffff0fff),
+    (0xfffffff0ffff), (0xffffff0fffff), (0xfffff0ffffff), (0xffff0fffffff),
+    (0xfff0ffffffff), (0xff0fffffffff), (0xf0ffffffffff), (0x0fffffffffff);
+> update count: 12
+
+select bit_and(v), bit_and(v) filter (where v <= 0xffffffff0fff) from test where v >= 0xff0fffffffff;
+> BIT_AND(V)      BIT_AND(V) FILTER (WHERE (V <= 281474976649215))
+> --------------- ------------------------------------------------
+> 280375465082880 280375465086975
+> rows: 1
+
+create index test_idx on test(v);
+
+select bit_and(v), bit_and(v) filter (where v <= 0xffffffff0fff) from test where v >= 0xff0fffffffff;
+> BIT_AND(V)      BIT_AND(V) FILTER (WHERE (V <= 281474976649215))
+> --------------- ------------------------------------------------
+> 280375465082880 280375465086975
+> rows: 1
+
+drop table test;
+> ok

h2/src/test/org/h2/test/scripts/functions/aggregate/bit-or.sql

@@ -2,3 +2,30 @@
 -- and the EPL 1.0 (http://h2database.com/html/license.html).
 -- Initial Developer: H2 Group
 --
+
+-- with filter condition
+
+-- with filter condition
+
+create table test(v bigint);
+> ok
+
+insert into test values (1), (2), (4), (8), (16), (32), (64), (128), (256), (512), (1024), (2048);
+> update count: 12
+
+select bit_or(v), bit_or(v) filter (where v >= 8) from test where v <= 512;
+> BIT_OR(V) BIT_OR(V) FILTER (WHERE (V >= 8))
+> --------- ---------------------------------
+> 1023      1016
+> rows: 1
+
+create index test_idx on test(v);
+
+select bit_or(v), bit_or(v) filter (where v >= 8) from test where v <= 512;
+> BIT_OR(V) BIT_OR(V) FILTER (WHERE (V >= 8))
+> --------- ---------------------------------
+> 1023      1016
+> rows: 1
+
+drop table test;
+> ok

h2/src/test/org/h2/test/scripts/functions/aggregate/count.sql

@@ -2,3 +2,34 @@
 -- and the EPL 1.0 (http://h2database.com/html/license.html).
 -- Initial Developer: H2 Group
 --
+
+-- with filter condition
+
+create table test(v int);
+> ok
+
+insert into test values (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12);
+> update count: 12
+
+select count(v), count(v) filter (where v >= 4) from test where v <= 10;
+> COUNT(V) COUNT(V) FILTER (WHERE (V >= 4))
+> -------- --------------------------------
+> 10       7
+> rows: 1
+
+create index test_idx on test(v);
+
+select count(v), count(v) filter (where v >= 4) from test where v <= 10;
+> COUNT(V) COUNT(V) FILTER (WHERE (V >= 4))
+> -------- --------------------------------
+> 10       7
+> rows: 1
+
+select count(v), count(v) filter (where v >= 4) from test;
+> COUNT(V) COUNT(V) FILTER (WHERE (V >= 4))
+> -------- --------------------------------
+> 12       9
+> rows: 1
+
+drop table test;
+> ok

h2/src/test/org/h2/test/scripts/functions/aggregate/group-concat.sql

@@ -2,3 +2,41 @@
 -- and the EPL 1.0 (http://h2database.com/html/license.html).
 -- Initial Developer: H2 Group
 --
+
+-- with filter condition
+
+create table test(v varchar);
+> ok
+
+insert into test values ('1'), ('2'), ('3'), ('4'), ('5'), ('6'), ('7'), ('8'), ('9');
+> update count: 9
+
+select group_concat(v order by v asc separator '-'),
+    group_concat(v order by v desc separator '-') filter (where v >= '4')
+    from test where v >= '2';
+> GROUP_CONCAT(V ORDER BY V SEPARATOR '-') GROUP_CONCAT(V ORDER BY V DESC SEPARATOR '-') FILTER (WHERE (V >= '4'))
+> ---------------------------------------- -----------------------------------------------------------------------
+> 2-3-4-5-6-7-8-9                          9-8-7-6-5-4
+> rows (ordered): 1
+
+create index test_idx on test(v);
+
+select group_concat(v order by v asc separator '-'),
+    group_concat(v order by v desc separator '-') filter (where v >= '4')
+    from test where v >= '2';
+> GROUP_CONCAT(V ORDER BY V SEPARATOR '-') GROUP_CONCAT(V ORDER BY V DESC SEPARATOR '-') FILTER (WHERE (V >= '4'))
+> ---------------------------------------- -----------------------------------------------------------------------
+> 2-3-4-5-6-7-8-9                          9-8-7-6-5-4
+> rows (ordered): 1
+
+select group_concat(v order by v asc separator '-'),
+    group_concat(v order by v desc separator '-') filter (where v >= '4')
+    from test;
+> GROUP_CONCAT(V ORDER BY V SEPARATOR '-') GROUP_CONCAT(V ORDER BY V DESC SEPARATOR '-') FILTER (WHERE (V >= '4'))
+> ---------------------------------------- -----------------------------------------------------------------------
+> 1-2-3-4-5-6-7-8-9                        9-8-7-6-5-4
+> rows (ordered): 1
+
+
+drop table test;
+> ok

h2/src/test/org/h2/test/scripts/functions/aggregate/max.sql

@@ -2,3 +2,34 @@
 -- and the EPL 1.0 (http://h2database.com/html/license.html).
 -- Initial Developer: H2 Group
 --
+
+-- with filter condition
+
+create table test(v int);
+> ok
+
+insert into test values (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12);
+> update count: 12
+
+select max(v), max(v) filter (where v <= 8) from test where v <= 10;
+> MAX(V) MAX(V) FILTER (WHERE (V <= 8))
+> ------ ------------------------------
+> 10     8
+> rows: 1
+
+create index test_idx on test(v);
+
+select max(v), max(v) filter (where v <= 8) from test where v <= 10;
+> MAX(V) MAX(V) FILTER (WHERE (V <= 8))
+> ------ ------------------------------
+> 10     8
+> rows: 1
+
+select max(v), max(v) filter (where v <= 8) from test;
+> MAX(V) MAX(V) FILTER (WHERE (V <= 8))
+> ------ ------------------------------
+> 12     8
+> rows: 1
+
+drop table test;
+> ok

h2/src/test/org/h2/test/scripts/functions/aggregate/median.sql

@@ -734,3 +734,72 @@ select median(v) from test;
 
 drop table test;
 > ok
+
+-- with filter condition
+
+create table test(v int);
+> ok
+
+insert into test values (10), (20), (30), (40), (50), (60), (70), (80), (90), (100), (110), (120);
+> update count: 12
+
+select median(v), median(v) filter (where v >= 40) from test where v <= 100;
+> MEDIAN(V) MEDIAN(V) FILTER (WHERE (V >= 40))
+> --------- ----------------------------------
+> 55        70
+> rows: 1
+
+create index test_idx on test(v);
+
+select median(v), median(v) filter (where v >= 40) from test where v <= 100;
+> MEDIAN(V) MEDIAN(V) FILTER (WHERE (V >= 40))
+> --------- ----------------------------------
+> 55        70
+> rows: 1
+
+select median(v), median(v) filter (where v >= 40) from test;
+> MEDIAN(V) MEDIAN(V) FILTER (WHERE (V >= 40))
+> --------- ----------------------------------
+> 65        80
+> rows: 1
+
+drop table test;
+> ok
+
+-- with filter and group by
+
+create table test(dept varchar, amount int);
+> ok
+
+insert into test values
+    ('First', 10), ('First', 10), ('First', 20), ('First', 30), ('First', 30),
+    ('Second', 5), ('Second', 4), ('Second', 20), ('Second', 22), ('Second', 300),
+    ('Third', 3), ('Third', 100), ('Third', 150), ('Third', 170), ('Third', 400);
+
+select dept, median(amount) from test group by dept order by dept;
+> DEPT   MEDIAN(AMOUNT)
+> ------ --------------
+> First  20
+> Second 20
+> Third  150
+> rows (ordered): 3
+
+select dept, median(amount) filter (where amount >= 20) from test group by dept order by dept;
+> DEPT   MEDIAN(AMOUNT) FILTER (WHERE (AMOUNT >= 20))
+> ------ --------------------------------------------
+> First  30
+> Second 22
+> Third  160
+> rows (ordered): 3
+
+select dept, median(amount) filter (where amount >= 20) from test
+    where (amount < 200) group by dept order by dept;
+> DEPT   MEDIAN(AMOUNT) FILTER (WHERE (AMOUNT >= 20))
+> ------ --------------------------------------------
+> First  30
+> Second 21
+> Third  150
+> rows (ordered): 3
+
+drop table test;
+> ok

h2/src/test/org/h2/test/scripts/functions/aggregate/min.sql

@@ -2,3 +2,34 @@
 -- and the EPL 1.0 (http://h2database.com/html/license.html).
 -- Initial Developer: H2 Group
 --
+
+-- with filter condition
+
+create table test(v int);
+> ok
+
+insert into test values (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12);
+> update count: 12
+
+select min(v), min(v) filter (where v >= 4) from test where v >= 2;
+> MIN(V) MIN(V) FILTER (WHERE (V >= 4))
+> ------ ------------------------------
+> 2      4
+> rows: 1
+
+create index test_idx on test(v);
+
+select min(v), min(v) filter (where v >= 4) from test where v >= 2;
+> MIN(V) MIN(V) FILTER (WHERE (V >= 4))
+> ------ ------------------------------
+> 2      4
+> rows: 1
+
+select min(v), min(v) filter (where v >= 4) from test;
+> MIN(V) MIN(V) FILTER (WHERE (V >= 4))
+> ------ ------------------------------
+> 1      4
+> rows: 1
+
+drop table test;
+> ok

h2/src/test/org/h2/test/scripts/functions/aggregate/sum.sql

@@ -2,3 +2,28 @@
 -- and the EPL 1.0 (http://h2database.com/html/license.html).
 -- Initial Developer: H2 Group
 --
+
+-- with filter condition
+
+create table test(v int);
+> ok
+
+insert into test values (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12);
+> update count: 12
+
+select sum(v), sum(v) filter (where v >= 4) from test where v <= 10;
+> SUM(V) SUM(V) FILTER (WHERE (V >= 4))
+> ------ ------------------------------
+> 55     49
+> rows: 1
+
+create index test_idx on test(v);
+
+select sum(v), sum(v) filter (where v >= 4) from test where v <= 10;
+> SUM(V) SUM(V) FILTER (WHERE (V >= 4))
+> ------ ------------------------------
+> 55     49
+> rows: 1
+
+drop table test;
+> ok