$not operator

src/main/java/io/stargate/sgv2/jsonapi/api/model/command/clause/filter/ArrayComparisonOperator.java

@@ -3,7 +3,9 @@
 /** List of element level operator that can be used in Filter clause */
 public enum ArrayComparisonOperator implements FilterOperator {
   ALL("$all"),
-  SIZE("$size");
+  SIZE("$size"),
+  // Will not be supported from outside
+  NOTANY("$notany");
 
   private String operator;
 
@@ -15,4 +17,16 @@ public enum ArrayComparisonOperator implements FilterOperator {
   public String getOperator() {
     return operator;
   }
+
+  @Override
+  public FilterOperator flip() {
+    switch (this) {
+      case ALL:
+        return NOTANY;
+      case NOTANY:
+        return ALL;
+      default:
+        return this;
+    }
+  }
 }

src/main/java/io/stargate/sgv2/jsonapi/api/model/command/clause/filter/ComparisonExpression.java

@@ -21,7 +21,7 @@ public class ComparisonExpression {
 
   private final String path;
 
-  @Valid @NotEmpty private final List<FilterOperation<?>> filterOperations;
+  @Valid @NotEmpty private List<FilterOperation<?>> filterOperations;
 
   private List<DBFilterBase> dbFilters;
 
@@ -33,6 +33,32 @@ public List<FilterOperation<?>> getFilterOperations() {
     return filterOperations;
   }
 
+  /** This method will be called when not operation is pushed down */
+  public void flip() {
+    List<FilterOperation<?>> filterOperations = new ArrayList<>(this.filterOperations.size());
+    for (FilterOperation<?> filterOperation : this.filterOperations) {
+      final FilterOperator flipedOperator = filterOperation.operator().flip();
+      JsonLiteral<?> operand =
+          getFlippedOperandValue(filterOperation.operator(), filterOperation.operand());
+      filterOperations.add(new ValueComparisonOperation<>(flipedOperator, operand));
+    }
+    this.filterOperations = filterOperations;
+  }
+
+  /**
+   * This method is used to flip the operand value when not operator is applied, e.g. $exists, $size
+   */
+  private JsonLiteral<?> getFlippedOperandValue(FilterOperator operator, JsonLiteral<?> operand) {
+    if (operator == ElementComparisonOperator.EXISTS) {
+      return new JsonLiteral<Boolean>(!((Boolean) operand.value()), operand.type());
+    } else if (operator == ArrayComparisonOperator.SIZE) {
+      return new JsonLiteral<BigDecimal>(
+          ((BigDecimal) operand.value()).multiply(new BigDecimal(-1)), operand.type());
+    } else {
+      return operand;
+    }
+  }
+
   public ComparisonExpression(
       @NotBlank(message = "json node path can not be null in filter") String path,
       List<FilterOperation<?>> filterOperations,

src/main/java/io/stargate/sgv2/jsonapi/api/model/command/clause/filter/ElementComparisonOperator.java

@@ -14,4 +14,9 @@ public enum ElementComparisonOperator implements FilterOperator {
   public String getOperator() {
     return operator;
   }
+
+  @Override
+  public FilterOperator flip() {
+    return this;
+  }
 }

src/main/java/io/stargate/sgv2/jsonapi/api/model/command/clause/filter/FilterOperator.java

@@ -9,6 +9,13 @@
 public interface FilterOperator {
   String getOperator();
 
+  /**
+   * Flip comparison operator when `$not` is pushed down
+   *
+   * @return
+   */
+  FilterOperator flip();
+
   class FilterOperatorUtils {
     private static Map<String, FilterOperator> operatorMap = new HashMap<>();
 
@@ -22,6 +29,8 @@ class FilterOperatorUtils {
       for (FilterOperator filterOperator : ArrayComparisonOperator.values()) {
         addComparisonOperator(filterOperator);
       }
+      // This should not be supported from outside
+      operatorMap.remove(ArrayComparisonOperator.NOTANY.getOperator());
     }
 
     private static void addComparisonOperator(FilterOperator filterOperator) {

src/main/java/io/stargate/sgv2/jsonapi/api/model/command/clause/filter/LogicalExpression.java

@@ -13,7 +13,8 @@ public class LogicalExpression {
 
   public enum LogicalOperator {
     AND("$and"),
-    OR("$or");
+    OR("$or"),
+    NOT("$not");
     private String operator;
 
     LogicalOperator(String operator) {
@@ -25,10 +26,67 @@ public String getOperator() {
     }
   }
 
-  private final LogicalOperator logicalRelation;
+  private LogicalOperator logicalRelation;
   private int totalComparisonExpressionCount;
   private int totalIdComparisonExpressionCount;
 
+  /** This method will flip the operators and operand if logical operator is not */
+  public void traverseForNot(LogicalExpression parent) {
+    List<LogicalExpression> tempLogicalExpressions = new ArrayList<>(logicalExpressions);
+    for (LogicalExpression logicalExpression : tempLogicalExpressions) {
+      logicalExpression.traverseForNot(this);
+    }
+
+    Iterator<LogicalExpression> iterator = logicalExpressions.iterator();
+    while (iterator.hasNext()) {
+      LogicalExpression logicalExpression = iterator.next();
+      if (logicalExpression.logicalRelation == LogicalOperator.NOT) {
+        iterator.remove();
+        this.totalComparisonExpressionCount =
+            this.totalComparisonExpressionCount - logicalExpression.totalComparisonExpressionCount;
+        this.totalIdComparisonExpressionCount =
+            this.totalIdComparisonExpressionCount
+                - logicalExpression.totalIdComparisonExpressionCount;
+      }
+    }
+
+    if (logicalRelation == LogicalOperator.NOT) {
+      flip();
+      addToParent(parent);
+    }
+  }
+
+  private void addToParent(LogicalExpression parent) {
+    logicalExpressions.stream().forEach(expression -> parent.addLogicalExpression(expression));
+    if (comparisonExpressions.size() > 1) {
+      // Multiple conditions in not, after push down will become or
+      final LogicalExpression orLogic = LogicalExpression.or();
+      comparisonExpressions.stream()
+          .forEach(comparisonExpression -> orLogic.addComparisonExpression(comparisonExpression));
+      parent.addLogicalExpression(orLogic);
+    } else {
+      if (comparisonExpressions.size() == 1) {
+        // Unary not, after push down will become additional condition
+        parent.addComparisonExpression(comparisonExpressions.get(0));
+      }
+    }
+    comparisonExpressions.clear();
+  }
+
+  private void flip() {
+    if (logicalRelation == LogicalOperator.AND) {
+      logicalRelation = LogicalOperator.OR;
+    } else if (logicalRelation == LogicalOperator.OR) {
+      logicalRelation = LogicalOperator.AND;
+    }
+    for (LogicalExpression logicalExpression : logicalExpressions) {
+      logicalExpression.flip();
+    }
+    for (ComparisonExpression comparisonExpression : comparisonExpressions) {
+      comparisonExpression.flip();
+    }
+  }
+
   public List<LogicalExpression> logicalExpressions;
   public List<ComparisonExpression> comparisonExpressions;
 
@@ -51,6 +109,10 @@ public static LogicalExpression or() {
     return new LogicalExpression(LogicalOperator.OR, 0, new ArrayList<>(), new ArrayList<>());
   }
 
+  public static LogicalExpression not() {
+    return new LogicalExpression(LogicalOperator.NOT, 0, new ArrayList<>(), new ArrayList<>());
+  }
+
   public void addLogicalExpression(LogicalExpression logicalExpression) {
     // skip empty logic expression
     if (logicalExpression.isEmpty()) {

src/main/java/io/stargate/sgv2/jsonapi/api/model/command/clause/filter/ValueComparisonOperator.java

@@ -24,4 +24,27 @@ public enum ValueComparisonOperator implements FilterOperator {
   public String getOperator() {
     return operator;
   }
+
+  @Override
+  public FilterOperator flip() {
+    switch (this) {
+      case EQ:
+        return NE;
+      case NE:
+        return EQ;
+      case IN:
+        return NIN;
+      case NIN:
+        return IN;
+      case GT:
+        return LTE;
+      case GTE:
+        return LT;
+      case LT:
+        return GTE;
+      case LTE:
+        return GT;
+    }
+    return this;
+  }
 }

src/main/java/io/stargate/sgv2/jsonapi/api/model/command/deserializers/FilterClauseDeserializer.java

@@ -45,6 +45,9 @@ public FilterClause deserialize(
     LogicalExpression implicitAnd = LogicalExpression.and();
     populateExpression(implicitAnd, filterNode);
     validate(implicitAnd);
+    // push down not operator
+    implicitAnd.traverseForNot(null);
+
     return new FilterClause(implicitAnd);
   }
 
@@ -94,6 +97,9 @@ private void populateExpression(
         case "$or":
           innerLogicalExpression = LogicalExpression.or();
           break;
+        case "$not":
+          innerLogicalExpression = LogicalExpression.not();
+          break;
         case DocumentConstants.Fields.VECTOR_EMBEDDING_FIELD:
           throw new JsonApiException(
               ErrorCode.INVALID_FILTER_EXPRESSION,

src/main/java/io/stargate/sgv2/jsonapi/service/operation/model/impl/DBFilterBase.java

@@ -595,10 +595,16 @@ boolean canAddField() {
   /** Filter for document where all values exists for an array */
   public static class AllFilter extends DBFilterBase {
     private final List<Object> arrayValue;
+    private final boolean negation;
 
-    public AllFilter(String path, List<Object> arrayValue) {
+    public AllFilter(String path, List<Object> arrayValue, boolean negation) {
       super(path);
       this.arrayValue = arrayValue;
+      this.negation = negation;
+    }
+
+    public boolean isNegation() {
+      return negation;
     }
 
     @Override
@@ -617,7 +623,7 @@ public List<BuiltCondition> getAll() {
         result.add(
             BuiltCondition.of(
                 DATA_CONTAINS,
-                Predicate.CONTAINS,
+                negation ? Predicate.NOT_CONTAINS : Predicate.CONTAINS,
                 new JsonTerm(getHashValue(new DocValueHasher(), getPath(), value))));
       }
       return result;
@@ -631,8 +637,8 @@ public BuiltCondition get() {
 
   /** Filter for document where array has specified number of elements */
   public static class SizeFilter extends MapFilterBase<Integer> {
-    public SizeFilter(String path, Integer size) {
-      super("array_size", path, Operator.MAP_EQUALS, size);
+    public SizeFilter(String path, Operator operator, Integer size) {
+      super("array_size", path, operator, size);
     }
 
     @Override

src/main/java/io/stargate/sgv2/jsonapi/service/operation/model/impl/ExpressionBuilder.java

@@ -112,7 +112,10 @@ private static Expression<BuiltCondition> buildExpressionRecursive(
           List<BuiltCondition> allFilterConditions = allFilter.getAll();
           List<Variable<BuiltCondition>> allFilterVariables =
               allFilterConditions.stream().map(Variable::of).toList();
-          conditionExpressions.add(ExpressionUtils.andOf(allFilterVariables));
+          conditionExpressions.add(
+              allFilter.isNegation()
+                  ? ExpressionUtils.orOf(allFilterVariables)
+                  : ExpressionUtils.andOf(allFilterVariables));
         } else if (dbFilter instanceof DBFilterBase.InFilter inFilter) {
           if (inFilter.operator.equals(DBFilterBase.InFilter.Operator.IN)) {
             hasInFilterThisLevel = true;

src/main/java/io/stargate/sgv2/jsonapi/service/resolver/model/impl/matcher/FilterableResolver.java

@@ -39,6 +39,7 @@ public abstract class FilterableResolver<T extends Command & Filterable> {
   private static final Object DYNAMIC_DATE_GROUP = new Object();
   private static final Object EXISTS_GROUP = new Object();
   private static final Object ALL_GROUP = new Object();
+  private static final Object NOT_ANY_GROUP = new Object();
   private static final Object SIZE_GROUP = new Object();
   private static final Object ARRAY_EQUALS = new Object();
   private static final Object SUB_DOC_EQUALS = new Object();
@@ -126,6 +127,8 @@ public FilterableResolver() {
         .compareValues("*", EnumSet.of(ElementComparisonOperator.EXISTS), JsonType.BOOLEAN)
         .capture(ALL_GROUP)
         .compareValues("*", EnumSet.of(ArrayComparisonOperator.ALL), JsonType.ARRAY)
+        .capture(NOT_ANY_GROUP)
+        .compareValues("*", EnumSet.of(ArrayComparisonOperator.NOTANY), JsonType.ARRAY)
         .capture(SIZE_GROUP)
         .compareValues("*", EnumSet.of(ArrayComparisonOperator.SIZE), JsonType.NUMBER)
         .capture(ARRAY_EQUALS)
@@ -292,12 +295,27 @@ public static List<DBFilterBase> findDynamic(CaptureExpression captureExpression
 
       if (captureExpression.marker() == ALL_GROUP) {
         List<Object> arrayValue = (List<Object>) filterOperation.operand().value();
-        filters.add(new DBFilterBase.AllFilter(captureExpression.path(), arrayValue));
+        filters.add(new DBFilterBase.AllFilter(captureExpression.path(), arrayValue, false));
+      }
+
+      if (captureExpression.marker() == NOT_ANY_GROUP) {
+        List<Object> arrayValue = (List<Object>) filterOperation.operand().value();
+        filters.add(new DBFilterBase.AllFilter(captureExpression.path(), arrayValue, true));
       }
 
       if (captureExpression.marker() == SIZE_GROUP) {
         BigDecimal bigDecimal = (BigDecimal) filterOperation.operand().value();
-        filters.add(new DBFilterBase.SizeFilter(captureExpression.path(), bigDecimal.intValue()));
+        // Flipping size operator will multiply the value by -1
+        // Negative means check array_size[?] != ?
+        int size = bigDecimal.intValue();
+        DBFilterBase.MapFilterBase.Operator operator;
+        if (size > 0) {
+          operator = DBFilterBase.MapFilterBase.Operator.MAP_EQUALS;
+        } else {
+          operator = DBFilterBase.MapFilterBase.Operator.MAP_NOT_EQUALS;
+        }
+        filters.add(
+            new DBFilterBase.SizeFilter(captureExpression.path(), operator, Math.abs(size)));
       }
 
       if (captureExpression.marker() == ARRAY_EQUALS) {