diff --git a/api/build.gradle b/api/build.gradle
index 5ce00169597..26fd419984d 100644
--- a/api/build.gradle
+++ b/api/build.gradle
@@ -16,6 +16,7 @@ dependencies {
     testImplementation group: 'junit', name: 'junit', version: '4.13.2'
     testImplementation group: 'org.hamcrest', name: 'hamcrest-library', version: "${hamcrest_version}"
     testImplementation group: 'org.mockito', name: 'mockito-core', version: "${mockito_version}"
+    testImplementation group: 'org.mockito', name: 'mockito-junit-jupiter', version: "${mockito_version}"
     testImplementation group: 'org.apache.calcite', name: 'calcite-testkit', version: '1.41.0'
 }
 
diff --git a/api/src/main/java/org/opensearch/sql/api/UnifiedQueryPlanner.java b/api/src/main/java/org/opensearch/sql/api/UnifiedQueryPlanner.java
index 6a524ec307a..9e981bdda17 100644
--- a/api/src/main/java/org/opensearch/sql/api/UnifiedQueryPlanner.java
+++ b/api/src/main/java/org/opensearch/sql/api/UnifiedQueryPlanner.java
@@ -32,6 +32,7 @@
 import org.opensearch.sql.calcite.SysLimit;
 import org.opensearch.sql.common.antlr.Parser;
 import org.opensearch.sql.common.antlr.SyntaxCheckException;
+import org.opensearch.sql.common.setting.Settings;
 import org.opensearch.sql.executor.QueryType;
 import org.opensearch.sql.ppl.antlr.PPLSyntaxParser;
 import org.opensearch.sql.ppl.parser.AstBuilder;
@@ -52,21 +53,26 @@ public class UnifiedQueryPlanner {
   /** Calcite framework configuration used during logical plan construction. */
   private final FrameworkConfig config;
 
+  private final Settings settings;
+
   /** AST-to-RelNode visitor that builds logical plans from the parsed AST. */
   private final CalciteRelNodeVisitor relNodeVisitor =
       new CalciteRelNodeVisitor(new EmptyDataSourceService());
 
   /**
-   * Constructs a UnifiedQueryPlanner for a given query type and schema root.
+   * Constructs a UnifiedQueryPlanner for a given query type, schema root, and settings.
    *
    * @param queryType the query language type (e.g., PPL)
    * @param rootSchema the root Calcite schema containing all catalogs and tables
    * @param defaultPath dot-separated path of schema to set as default schema
+   * @param settings configuration settings for query processing
    */
-  public UnifiedQueryPlanner(QueryType queryType, SchemaPlus rootSchema, String defaultPath) {
+  public UnifiedQueryPlanner(
+      QueryType queryType, SchemaPlus rootSchema, String defaultPath, Settings settings) {
     this.queryType = queryType;
     this.parser = buildQueryParser(queryType);
     this.config = buildCalciteConfig(rootSchema, defaultPath);
+    this.settings = settings;
   }
 
   /**
@@ -124,7 +130,8 @@ private UnresolvedPlan parse(String query) {
     ParseTree cst = parser.parse(query);
     AstStatementBuilder astStmtBuilder =
         new AstStatementBuilder(
-            new AstBuilder(query), AstStatementBuilder.StatementBuilderContext.builder().build());
+            new AstBuilder(query, settings),
+            AstStatementBuilder.StatementBuilderContext.builder().build());
     Statement statement = cst.accept(astStmtBuilder);
 
     if (statement instanceof Query) {
@@ -164,6 +171,7 @@ public static class Builder {
     private String defaultNamespace;
     private QueryType queryType;
     private boolean cacheMetadata;
+    private Settings settings;
 
     /**
      * Sets the query language frontend to be used by the planner.
@@ -176,6 +184,17 @@ public Builder language(QueryType queryType) {
       return this;
     }
 
+    /**
+     * Sets the settings for query processing configuration.
+     *
+     * @param settings the Settings instance for configuration
+     * @return this builder instance
+     */
+    public Builder settings(Settings settings) {
+      this.settings = settings;
+      return this;
+    }
+
     /**
      * Registers a catalog with the specified name and its associated schema. The schema can be a
      * flat or nested structure (e.g., catalog → schema → table), depending on how data is
@@ -221,7 +240,7 @@ public UnifiedQueryPlanner build() {
       Objects.requireNonNull(queryType, "Must specify language before build");
       SchemaPlus rootSchema = CalciteSchema.createRootSchema(true, cacheMetadata).plus();
       catalogs.forEach(rootSchema::add);
-      return new UnifiedQueryPlanner(queryType, rootSchema, defaultNamespace);
+      return new UnifiedQueryPlanner(queryType, rootSchema, defaultNamespace, settings);
     }
   }
 }
diff --git a/api/src/test/java/org/opensearch/sql/api/UnifiedQueryPlannerTest.java b/api/src/test/java/org/opensearch/sql/api/UnifiedQueryPlannerTest.java
index 754e36c092e..f40d63db1fe 100644
--- a/api/src/test/java/org/opensearch/sql/api/UnifiedQueryPlannerTest.java
+++ b/api/src/test/java/org/opensearch/sql/api/UnifiedQueryPlannerTest.java
@@ -13,9 +13,14 @@
 import org.apache.calcite.schema.Schema;
 import org.apache.calcite.schema.impl.AbstractSchema;
 import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
 import org.opensearch.sql.common.antlr.SyntaxCheckException;
+import org.opensearch.sql.common.setting.Settings;
 import org.opensearch.sql.executor.QueryType;
 
+@RunWith(MockitoJUnitRunner.class)
 public class UnifiedQueryPlannerTest extends UnifiedQueryTestBase {
 
   /** Test catalog consists of test schema above */
@@ -27,6 +32,8 @@ protected Map<String, Schema> getSubSchemaMap() {
         }
       };
 
+  @Mock private Settings testSettings;
+
   @Test
   public void testPPLQueryPlanning() {
     UnifiedQueryPlanner planner =
@@ -155,4 +162,17 @@ public void testPlanPropagatingSyntaxCheckException() {
 
     planner.plan("source = employees | eval"); // Trigger syntax error from parser
   }
+
+  @Test
+  public void testJoinQuery() {
+    UnifiedQueryPlanner planner =
+        UnifiedQueryPlanner.builder()
+            .language(QueryType.PPL)
+            .catalog("opensearch", testSchema)
+            .defaultNamespace("opensearch")
+            .settings(testSettings)
+            .build();
+
+    planner.plan("source = employees | join on employees.id = payslips.id payslips");
+  }
 }
diff --git a/api/src/test/java/org/opensearch/sql/api/UnifiedQueryTestBase.java b/api/src/test/java/org/opensearch/sql/api/UnifiedQueryTestBase.java
index f63bfed09ec..e679c4b2488 100644
--- a/api/src/test/java/org/opensearch/sql/api/UnifiedQueryTestBase.java
+++ b/api/src/test/java/org/opensearch/sql/api/UnifiedQueryTestBase.java
@@ -31,7 +31,7 @@ public void setUp() {
         new AbstractSchema() {
           @Override
           protected Map<String, Table> getTableMap() {
-            return Map.of("employees", createEmployeesTable());
+            return Map.of("employees", createEmployeesTable(), "payslips", createPayslipsTable());
           }
         };
 
@@ -57,4 +57,18 @@ public RelDataType getRowType(RelDataTypeFactory typeFactory) {
       }
     };
   }
+
+  protected Table createPayslipsTable() {
+    return new AbstractTable() {
+      @Override
+      public RelDataType getRowType(RelDataTypeFactory typeFactory) {
+        return typeFactory.createStructType(
+            List.of(
+                typeFactory.createSqlType(SqlTypeName.INTEGER),
+                typeFactory.createSqlType(SqlTypeName.DATE),
+                typeFactory.createSqlType(SqlTypeName.FLOAT)),
+            List.of("id", "date", "salary"));
+      }
+    };
+  }
 }