diff --git a/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4 b/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4
index 4b4e64c1a..f6cd0d4ee 100644
--- a/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4
+++ b/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4
@@ -27,8 +27,6 @@ queryStatement
 // commands
 pplCommands
    : searchCommand
-   | describeCommand
-   | showDataSourcesCommand
    ;
 
 commands
@@ -37,18 +35,8 @@ commands
    | fieldsCommand
    | renameCommand
    | statsCommand
-   | dedupCommand
    | sortCommand
-   | evalCommand
    | headCommand
-   | topCommand
-   | rareCommand
-   | grokCommand
-   | parseCommand
-   | patternsCommand
-   | kmeansCommand
-   | adCommand
-   | mlCommand
    ;
 
 searchCommand
@@ -190,8 +178,6 @@ mlArg
 fromClause
    : SOURCE EQUAL tableSourceClause
    | INDEX EQUAL tableSourceClause
-   | SOURCE EQUAL tableFunction
-   | INDEX EQUAL tableFunction
    ;
 
 tableSourceClause
@@ -248,10 +234,6 @@ statsFunctionName
    | SUM
    | MIN
    | MAX
-   | VAR_SAMP
-   | VAR_POP
-   | STDDEV_SAMP
-   | STDDEV_POP
    ;
 
 takeAggFunction
@@ -281,24 +263,17 @@ logicalExpression
 
 comparisonExpression
    : left = valueExpression comparisonOperator right = valueExpression  # compareExpr
-   | valueExpression IN valueList                                       # inExpr
    ;
 
 valueExpression
    : left = valueExpression binaryOperator = (STAR | DIVIDE | MODULE) right = valueExpression   # binaryArithmetic
    | left = valueExpression binaryOperator = (PLUS | MINUS) right = valueExpression             # binaryArithmetic
    | primaryExpression                                                                          # valueExpressionDefault
-   | positionFunction                                                                           # positionFunctionCall
-   | extractFunction                                                                            # extractFunctionCall
-   | getFormatFunction                                                                          # getFormatFunctionCall
-   | timestampFunction                                                                          # timestampFunctionCall
    | LT_PRTHS valueExpression RT_PRTHS                                                          # parentheticValueExpr
    ;
 
 primaryExpression
-   : evalFunctionCall
-   | dataTypeFunctionCall
-   | fieldExpression
+   : fieldExpression
    | literalValue
    ;
 
@@ -700,8 +675,7 @@ multiFieldRelevanceFunctionName
 
 // literals and values
 literalValue
-   : intervalLiteral
-   | stringLiteral
+   : stringLiteral
    | integerLiteral
    | decimalLiteral
    | booleanLiteral
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstBuilder.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstBuilder.java
index a810ea180..ce9eea769 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstBuilder.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstBuilder.java
@@ -287,11 +287,7 @@ public UnresolvedPlan visitTopCommand(OpenSearchPPLParser.TopCommandContext ctx)
   /** From clause. */
   @Override
   public UnresolvedPlan visitFromClause(OpenSearchPPLParser.FromClauseContext ctx) {
-    if (ctx.tableFunction() != null) {
-      return visitTableFunction(ctx.tableFunction());
-    } else {
-      return visitTableSourceClause(ctx.tableSourceClause());
-    }
+    return visitTableSourceClause(ctx.tableSourceClause());
   }
 
   @Override
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstExpressionBuilder.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstExpressionBuilder.java
index 3344cd7c2..8cfbc15d5 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstExpressionBuilder.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstExpressionBuilder.java
@@ -243,55 +243,6 @@ public UnresolvedExpression visitPositionFunction(
                 Arrays.asList(visitFunctionArg(ctx.functionArg(0)), visitFunctionArg(ctx.functionArg(1))));
     }
 
-    @Override
-    public UnresolvedExpression visitExtractFunctionCall(
-            OpenSearchPPLParser.ExtractFunctionCallContext ctx) {
-        return new Function(
-                ctx.extractFunction().EXTRACT().toString(), getExtractFunctionArguments(ctx));
-    }
-
-    private List<UnresolvedExpression> getExtractFunctionArguments(
-            OpenSearchPPLParser.ExtractFunctionCallContext ctx) {
-        List<UnresolvedExpression> args =
-                Arrays.asList(
-                        new Literal(ctx.extractFunction().datetimePart().getText(), DataType.STRING),
-                        visitFunctionArg(ctx.extractFunction().functionArg()));
-        return args;
-    }
-
-    @Override
-    public UnresolvedExpression visitGetFormatFunctionCall(
-            OpenSearchPPLParser.GetFormatFunctionCallContext ctx) {
-        return new Function(
-                ctx.getFormatFunction().GET_FORMAT().toString(), getFormatFunctionArguments(ctx));
-    }
-
-    private List<UnresolvedExpression> getFormatFunctionArguments(
-            OpenSearchPPLParser.GetFormatFunctionCallContext ctx) {
-        List<UnresolvedExpression> args =
-                Arrays.asList(
-                        new Literal(ctx.getFormatFunction().getFormatType().getText(), DataType.STRING),
-                        visitFunctionArg(ctx.getFormatFunction().functionArg()));
-        return args;
-    }
-
-    @Override
-    public UnresolvedExpression visitTimestampFunctionCall(
-            OpenSearchPPLParser.TimestampFunctionCallContext ctx) {
-        return new Function(
-                ctx.timestampFunction().timestampFunctionName().getText(), timestampFunctionArguments(ctx));
-    }
-
-    private List<UnresolvedExpression> timestampFunctionArguments(
-            OpenSearchPPLParser.TimestampFunctionCallContext ctx) {
-        List<UnresolvedExpression> args =
-                Arrays.asList(
-                        new Literal(ctx.timestampFunction().simpleDateTimePart().getText(), DataType.STRING),
-                        visitFunctionArg(ctx.timestampFunction().firstArg),
-                        visitFunctionArg(ctx.timestampFunction().secondArg));
-        return args;
-    }
-
     /**
      * Literal and value.
      */