diff --git a/jOOQ/src/main/java/org/jooq/conf/Settings.java b/jOOQ/src/main/java/org/jooq/conf/Settings.java
index 978d818a2a..a779e64530 100644
--- a/jOOQ/src/main/java/org/jooq/conf/Settings.java
+++ b/jOOQ/src/main/java/org/jooq/conf/Settings.java
@@ -187,6 +187,8 @@ public class Settings
     @XmlElement(defaultValue = "true")
     protected Boolean transformPatternsCaseUnreachableClauses = true;
     @XmlElement(defaultValue = "true")
+    protected Boolean transformPatternsCaseDistinctToDecode = true;
+    @XmlElement(defaultValue = "true")
     protected Boolean transformPatternsCaseMergeWhenWhen = true;
     @XmlElement(defaultValue = "true")
     protected Boolean transformPatternsCaseMergeWhenElse = true;
@@ -2316,6 +2318,41 @@ public class Settings
         this.transformPatternsCaseUnreachableClauses = value;
     }
 
+    /**
+     * Transform <code>CASE WHEN a IS NOT DISTINCT FROM b …</code> to an equivalent <code>DECODE</code> function.
+     * <p>
+     * When all <code>WHEN</code> clauses of a <code>CASE</code> expression use the <code>DISTINCT</code> predicate, then the
+     * <code>CASE</code> expression can be transformed into a <code>DECODE</code> function call:
+     * <ul>
+     * <li><code>CASE WHEN a IS NOT DISTINCT FROM b THEN 1 END</code> is equivalent to <code>DECODE(a, b, 1)</code></li>
+     * <li><code>CASE WHEN a IS NOT DISTINCT FROM b THEN 1 ELSE 2 END</code> is equivalent to <code>DECODE(a, b, 1, 2)</code></li>
+     * <li><code>CASE WHEN a IS NOT DISTINCT FROM b THEN 1 WHEN a IS NOT DISTINCT FROM c THEN 2 END</code> is equivalent to <code>DECODE(a, b, 1, c, 2)</code></li>
+     * <li><code>CASE WHEN a IS NOT DISTINCT FROM b THEN 1 WHEN a IS NOT DISTINCT FROM c THEN 2 ELSE 3 END</code> is equivalent to <code>DECODE(a, b, 1, c, 2, 3)</code></li>
+     * </ul>
+     * <p>
+     * This feature is available in the commercial distribution only.
+     * 
+     * @return
+     *     possible object is
+     *     {@link Boolean }
+     *     
+     */
+    public Boolean isTransformPatternsCaseDistinctToDecode() {
+        return transformPatternsCaseDistinctToDecode;
+    }
+
+    /**
+     * Sets the value of the transformPatternsCaseDistinctToDecode property.
+     * 
+     * @param value
+     *     allowed object is
+     *     {@link Boolean }
+     *     
+     */
+    public void setTransformPatternsCaseDistinctToDecode(Boolean value) {
+        this.transformPatternsCaseDistinctToDecode = value;
+    }
+
     /**
      * Transform <code>CASE WHEN a THEN x WHEN b THEN x END</code> to <code>CASE WHEN a OR b THEN x END</code>.
      * <p>
@@ -5541,6 +5578,11 @@ public class Settings
         return this;
     }
 
+    public Settings withTransformPatternsCaseDistinctToDecode(Boolean value) {
+        setTransformPatternsCaseDistinctToDecode(value);
+        return this;
+    }
+
     public Settings withTransformPatternsCaseMergeWhenWhen(Boolean value) {
         setTransformPatternsCaseMergeWhenWhen(value);
         return this;
@@ -6555,6 +6597,7 @@ public class Settings
         builder.append("transformPatternsCaseElseNull", transformPatternsCaseElseNull);
         builder.append("transformPatternsCaseElseCase", transformPatternsCaseElseCase);
         builder.append("transformPatternsCaseUnreachableClauses", transformPatternsCaseUnreachableClauses);
+        builder.append("transformPatternsCaseDistinctToDecode", transformPatternsCaseDistinctToDecode);
         builder.append("transformPatternsCaseMergeWhenWhen", transformPatternsCaseMergeWhenWhen);
         builder.append("transformPatternsCaseMergeWhenElse", transformPatternsCaseMergeWhenElse);
         builder.append("transformPatternsCaseToCaseAbbreviation", transformPatternsCaseToCaseAbbreviation);
@@ -7310,6 +7353,15 @@ public class Settings
                 return false;
             }
         }
+        if (transformPatternsCaseDistinctToDecode == null) {
+            if (other.transformPatternsCaseDistinctToDecode!= null) {
+                return false;
+            }
+        } else {
+            if (!transformPatternsCaseDistinctToDecode.equals(other.transformPatternsCaseDistinctToDecode)) {
+                return false;
+            }
+        }
         if (transformPatternsCaseMergeWhenWhen == null) {
             if (other.transformPatternsCaseMergeWhenWhen!= null) {
                 return false;
@@ -8483,6 +8535,7 @@ public class Settings
         result = ((prime*result)+((transformPatternsCaseElseNull == null)? 0 :transformPatternsCaseElseNull.hashCode()));
         result = ((prime*result)+((transformPatternsCaseElseCase == null)? 0 :transformPatternsCaseElseCase.hashCode()));
         result = ((prime*result)+((transformPatternsCaseUnreachableClauses == null)? 0 :transformPatternsCaseUnreachableClauses.hashCode()));
+        result = ((prime*result)+((transformPatternsCaseDistinctToDecode == null)? 0 :transformPatternsCaseDistinctToDecode.hashCode()));
         result = ((prime*result)+((transformPatternsCaseMergeWhenWhen == null)? 0 :transformPatternsCaseMergeWhenWhen.hashCode()));
         result = ((prime*result)+((transformPatternsCaseMergeWhenElse == null)? 0 :transformPatternsCaseMergeWhenElse.hashCode()));
         result = ((prime*result)+((transformPatternsCaseToCaseAbbreviation == null)? 0 :transformPatternsCaseToCaseAbbreviation.hashCode()));
diff --git a/jOOQ/src/main/java/org/jooq/impl/CaseImpl.java b/jOOQ/src/main/java/org/jooq/impl/CaseImpl.java
index 186aedc7c1..a9168439e5 100644
--- a/jOOQ/src/main/java/org/jooq/impl/CaseImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/CaseImpl.java
@@ -62,7 +62,7 @@ final class CaseImpl implements Case, UTransient {
 
     @Override
     public final <V> CaseValueStep<V> value(Field<V> value) {
-        return new CaseValueStepImpl<>(value);
+        return new CaseSimpleValueStep<>(value);
     }
 
     @Override
@@ -72,7 +72,7 @@ final class CaseImpl implements Case, UTransient {
 
     @Override
     public final <T> CaseConditionStep<T> when(Condition condition, Field<T> result) {
-        return new CaseConditionStepImpl<>(condition, result);
+        return new CaseSearched<>(condition, result);
     }
 
     @Override
diff --git a/jOOQ/src/main/java/org/jooq/impl/CaseConditionStepImpl.java b/jOOQ/src/main/java/org/jooq/impl/CaseSearched.java
similarity index 90%
rename from jOOQ/src/main/java/org/jooq/impl/CaseConditionStepImpl.java
rename to jOOQ/src/main/java/org/jooq/impl/CaseSearched.java
index 2fcfdae0d0..da10ef549d 100644
--- a/jOOQ/src/main/java/org/jooq/impl/CaseConditionStepImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/CaseSearched.java
@@ -39,6 +39,7 @@ package org.jooq.impl;
 
 import static java.lang.Boolean.TRUE;
 // ...
+import static org.jooq.impl.DSL.NULL;
 import static org.jooq.impl.DSL.one;
 import static org.jooq.impl.DSL.select;
 import static org.jooq.impl.Keywords.K_CASE;
@@ -64,14 +65,13 @@ import org.jooq.Function2;
 import org.jooq.Record1;
 // ...
 import org.jooq.Select;
-import org.jooq.impl.QOM.CaseSearched;
 import org.jooq.impl.QOM.Tuple2;
 import org.jooq.impl.QOM.UnmodifiableList;
 
 /**
  * @author Lukas Eder
  */
-final class CaseConditionStepImpl<T>
+final class CaseSearched<T>
 extends
     AbstractField<T>
 implements
@@ -80,15 +80,15 @@ implements
 {
 
     private final List<Tuple2<Condition, Field<T>>> when;
-    private Field<T>                                 else_;
+    private Field<T>                                else_;
 
-    CaseConditionStepImpl(DataType<T> type) {
+    CaseSearched(DataType<T> type) {
         super(NQ_CASE, type);
 
         this.when = new QueryPartList<>();
     }
 
-    CaseConditionStepImpl(Condition condition, Field<T> result) {
+    CaseSearched(Condition condition, Field<T> result) {
         this(result.getDataType());
 
         when(condition, result);
@@ -163,7 +163,14 @@ implements
 
     @Override
     public final void accept(Context<?> ctx) {
-        switch (ctx.family()) {
+        if (when.isEmpty()) {
+            if (else_ != null)
+                ctx.visit(else_);
+            else
+                ctx.visit(NULL(getDataType()));
+        }
+        else {
+            switch (ctx.family()) {
 
 
 
@@ -174,9 +181,10 @@ implements
 
 
 
-            default:
-                acceptNative(ctx);
-                break;
+                default:
+                    acceptNative(ctx);
+                    break;
+            }
         }
     }
 
@@ -265,7 +273,7 @@ implements
     @Override
     public final Function2<? super UnmodifiableList<? extends Tuple2<Condition, Field<T>>>, ? super Field<T>, ? extends CaseSearched<T>> $constructor() {
         return (w, e) -> {
-            CaseConditionStepImpl<T> r = new CaseConditionStepImpl<>(getDataType());
+            CaseSearched<T> r = new CaseSearched<>(getDataType());
             w.forEach(t -> r.when(t.$1(), t.$2()));
             r.else_(e);
             return r;
diff --git a/jOOQ/src/main/java/org/jooq/impl/CaseWhenStepImpl.java b/jOOQ/src/main/java/org/jooq/impl/CaseSimple.java
similarity index 87%
rename from jOOQ/src/main/java/org/jooq/impl/CaseWhenStepImpl.java
rename to jOOQ/src/main/java/org/jooq/impl/CaseSimple.java
index f792548cf0..edd995f384 100644
--- a/jOOQ/src/main/java/org/jooq/impl/CaseWhenStepImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/CaseSimple.java
@@ -38,6 +38,7 @@
 package org.jooq.impl;
 
 import static java.lang.Boolean.TRUE;
+import static org.jooq.impl.DSL.NULL;
 import static org.jooq.impl.Keywords.K_CASE;
 import static org.jooq.impl.Keywords.K_ELSE;
 import static org.jooq.impl.Keywords.K_END;
@@ -60,14 +61,13 @@ import org.jooq.DataType;
 import org.jooq.Field;
 import org.jooq.Function3;
 // ...
-import org.jooq.impl.QOM.CaseSimple;
 import org.jooq.impl.QOM.Tuple2;
 import org.jooq.impl.QOM.UnmodifiableList;
 
 /**
  * @author Lukas Eder
  */
-final class CaseWhenStepImpl<V, T>
+final class CaseSimple<V, T>
 extends
     AbstractField<T>
 implements
@@ -75,23 +75,23 @@ implements
     QOM.CaseSimple<V, T>
 {
 
-    private final Field<V>                          value;
+    private final Field<V>                         value;
     private final List<Tuple2<Field<V>, Field<T>>> when;
-    private Field<T>                                else_;
+    private Field<T>                               else_;
 
-    CaseWhenStepImpl(Field<V> value, Field<V> compareValue, Field<T> result) {
+    CaseSimple(Field<V> value, Field<V> compareValue, Field<T> result) {
         this(value, result.getDataType());
 
         when(compareValue, result);
     }
 
-    CaseWhenStepImpl(Field<V> value, Map<? extends Field<V>, ? extends Field<T>> map) {
+    CaseSimple(Field<V> value, Map<? extends Field<V>, ? extends Field<T>> map) {
         this(value, dataType(map));
 
         mapFields(map);
     }
 
-    CaseWhenStepImpl(Field<V> value, DataType<T> type) {
+    CaseSimple(Field<V> value, DataType<T> type) {
         super(NQ_CASE, type);
 
         this.value = value;
@@ -168,7 +168,14 @@ implements
 
     @Override
     public final void accept(Context<?> ctx) {
-        switch (ctx.family()) {
+        if (when.isEmpty()) {
+            if (else_ != null)
+                ctx.visit(else_);
+            else
+                ctx.visit(NULL(getDataType()));
+        }
+        else {
+            switch (ctx.family()) {
 
 
 
@@ -179,14 +186,15 @@ implements
 
 
 
-            // The DERBY dialect doesn't support the simple CASE clause
-            case DERBY:
-                acceptSearched(ctx);
-                break;
+                // The DERBY dialect doesn't support the simple CASE clause
+                case DERBY:
+                    acceptSearched(ctx);
+                    break;
 
-            default:
-                acceptNative(ctx);
-                break;
+                default:
+                    acceptNative(ctx);
+                    break;
+            }
         }
     }
 
@@ -284,7 +292,7 @@ implements
     @Override
     public final Function3<? super Field<V>, ? super UnmodifiableList<? extends Tuple2<Field<V>, Field<T>>>, ? super Field<T>, ? extends CaseSimple<V, T>> $constructor() {
         return (v, w, e) -> {
-            CaseWhenStepImpl<V, T> r = new CaseWhenStepImpl<>(v, getDataType());
+            CaseSimple<V, T> r = new CaseSimple<>(v, getDataType());
             w.forEach(t -> r.when(t.$1(), t.$2()));
             r.else_(e);
             return r;
diff --git a/jOOQ/src/main/java/org/jooq/impl/CaseValueStepImpl.java b/jOOQ/src/main/java/org/jooq/impl/CaseSimpleValueStep.java
similarity index 92%
rename from jOOQ/src/main/java/org/jooq/impl/CaseValueStepImpl.java
rename to jOOQ/src/main/java/org/jooq/impl/CaseSimpleValueStep.java
index d2715b5cf1..c763222ce3 100644
--- a/jOOQ/src/main/java/org/jooq/impl/CaseValueStepImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/CaseSimpleValueStep.java
@@ -52,11 +52,11 @@ import org.jooq.impl.QOM.UTransient;
  *
  * @author Lukas Eder
  */
-final class CaseValueStepImpl<V> implements CaseValueStep<V>, UTransient {
+final class CaseSimpleValueStep<V> implements CaseValueStep<V>, UTransient {
 
     private final Field<V> value;
 
-    CaseValueStepImpl(Field<V> value) {
+    CaseSimpleValueStep(Field<V> value) {
         this.value = value;
     }
 
@@ -82,7 +82,7 @@ final class CaseValueStepImpl<V> implements CaseValueStep<V>, UTransient {
 
     @Override
     public final <T> CaseWhenStep<V, T> when(Field<V> compareValue, Field<T> result) {
-        return new CaseWhenStepImpl<>(value, compareValue, result);
+        return new CaseSimple<>(value, compareValue, result);
     }
 
     @Override
@@ -99,6 +99,6 @@ final class CaseValueStepImpl<V> implements CaseValueStep<V>, UTransient {
 
     @Override
     public final <T> CaseWhenStep<V, T> mapFields(Map<? extends Field<V>, ? extends Field<T>> fields) {
-        return new CaseWhenStepImpl<>(value, fields);
+        return new CaseSimple<>(value, fields);
     }
 }
diff --git a/jOOQ/src/main/java/org/jooq/impl/MergeImpl.java b/jOOQ/src/main/java/org/jooq/impl/MergeImpl.java
index 02390a1e57..8d11622525 100644
--- a/jOOQ/src/main/java/org/jooq/impl/MergeImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/MergeImpl.java
@@ -1629,7 +1629,7 @@ implements
                     for (Entry<FieldOrRow, FieldOrRowOrSelect> e : m.updateMap.entrySet()) {
                         FieldOrRowOrSelect exp = update.updateMap.get(e.getKey());
 
-                        if (exp instanceof CaseConditionStepImpl c)
+                        if (exp instanceof CaseSearched c)
                             c.when(negate.and(condition), e.getValue());
 
                         // [#10523] [#13325] TODO: ClassCastException when we're using Row here, once supported
diff --git a/jOOQ/src/main/java/org/jooq/impl/Patterns.java b/jOOQ/src/main/java/org/jooq/impl/Patterns.java
index d7954a63aa..4867970dac 100644
--- a/jOOQ/src/main/java/org/jooq/impl/Patterns.java
+++ b/jOOQ/src/main/java/org/jooq/impl/Patterns.java
@@ -2117,6 +2117,64 @@ package org.jooq.impl;
 
 
 
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
 
 
 
diff --git a/jOOQ/src/main/resources/org/jooq/xsd/jooq-runtime-3.18.0.xsd b/jOOQ/src/main/resources/org/jooq/xsd/jooq-runtime-3.18.0.xsd
index 7816d34185..db5204be9d 100644
--- a/jOOQ/src/main/resources/org/jooq/xsd/jooq-runtime-3.18.0.xsd
+++ b/jOOQ/src/main/resources/org/jooq/xsd/jooq-runtime-3.18.0.xsd
@@ -615,6 +615,21 @@ Case clauses can be proven to be unreachable, and thus removed:
 This feature is available in the commercial distribution only.]]></jxb:javadoc></jxb:property></appinfo></annotation>
       </element>
       
+      <element name="transformPatternsCaseDistinctToDecode" type="boolean" minOccurs="0" maxOccurs="1" default="true">
+        <annotation><appinfo><jxb:property><jxb:javadoc><![CDATA[Transform <code>CASE WHEN a IS NOT DISTINCT FROM b ..</code> to an equivalent <code>DECODE</code> function.
+<p>
+When all <code>WHEN</code> clauses of a <code>CASE</code> expression use the <code>DISTINCT</code> predicate, then the
+<code>CASE</code> expression can be transformed into a <code>DECODE</code> function call:
+<ul>
+<li><code>CASE WHEN a IS NOT DISTINCT FROM b THEN 1 END</code> is equivalent to <code>DECODE(a, b, 1)</code></li>
+<li><code>CASE WHEN a IS NOT DISTINCT FROM b THEN 1 ELSE 2 END</code> is equivalent to <code>DECODE(a, b, 1, 2)</code></li>
+<li><code>CASE WHEN a IS NOT DISTINCT FROM b THEN 1 WHEN a IS NOT DISTINCT FROM c THEN 2 END</code> is equivalent to <code>DECODE(a, b, 1, c, 2)</code></li>
+<li><code>CASE WHEN a IS NOT DISTINCT FROM b THEN 1 WHEN a IS NOT DISTINCT FROM c THEN 2 ELSE 3 END</code> is equivalent to <code>DECODE(a, b, 1, c, 2, 3)</code></li>
+</ul>
+<p>
+This feature is available in the commercial distribution only.]]></jxb:javadoc></jxb:property></appinfo></annotation>
+      </element>
+      
       <element name="transformPatternsCaseMergeWhenWhen" type="boolean" minOccurs="0" maxOccurs="1" default="true">
         <annotation><appinfo><jxb:property><jxb:javadoc><![CDATA[Transform <code>CASE WHEN a THEN x WHEN b THEN x END</code> to <code>CASE WHEN a OR b THEN x END</code>.
 <p>