diff --git a/core/src/main/java/org/apache/calcite/adapter/jdbc/JdbcCorrelationDataContext.java b/core/src/main/java/org/apache/calcite/adapter/jdbc/JdbcCorrelationDataContext.java
index f89f8726f19..802e490d83f 100644
--- a/core/src/main/java/org/apache/calcite/adapter/jdbc/JdbcCorrelationDataContext.java
+++ b/core/src/main/java/org/apache/calcite/adapter/jdbc/JdbcCorrelationDataContext.java
@@ -29,7 +29,7 @@
  * A special DataContext which handles correlation variable for batch nested loop joins.
  */
 public class JdbcCorrelationDataContext implements DataContext {
-  public static final int OFFSET = 10000;
+  public static final int OFFSET = Integer.MAX_VALUE - 10000;
 
   private final DataContext delegate;
   private final Object[] parameters;
diff --git a/core/src/main/java/org/apache/calcite/adapter/jdbc/JdbcCorrelationDataContextBuilder.java b/core/src/main/java/org/apache/calcite/adapter/jdbc/JdbcCorrelationDataContextBuilder.java
index 8c850580b87..1877fdbd1e2 100644
--- a/core/src/main/java/org/apache/calcite/adapter/jdbc/JdbcCorrelationDataContextBuilder.java
+++ b/core/src/main/java/org/apache/calcite/adapter/jdbc/JdbcCorrelationDataContextBuilder.java
@@ -21,8 +21,12 @@
 import java.lang.reflect.Type;
 
 /**
- * A class to build an object of type JdbcCorrelationDataContext.
+ * An interface to collect all correlation variables
+ * required to create a JdbcCorrelationDataContext.
  */
-public interface JdbcCorrelationDataContextBuilder {
+interface JdbcCorrelationDataContextBuilder {
+  /**
+   * Collect a correlation variable.
+   */
   int add(CorrelationId id, int ordinal, Type type);
 }
diff --git a/core/src/main/java/org/apache/calcite/adapter/jdbc/JdbcImplementor.java b/core/src/main/java/org/apache/calcite/adapter/jdbc/JdbcImplementor.java
index 294c08858e7..1485c4788e8 100644
--- a/core/src/main/java/org/apache/calcite/adapter/jdbc/JdbcImplementor.java
+++ b/core/src/main/java/org/apache/calcite/adapter/jdbc/JdbcImplementor.java
@@ -39,10 +39,10 @@ public class JdbcImplementor extends RelToSqlConverter {
   private final JdbcCorrelationDataContextBuilder dataContextBuilder;
   private final JavaTypeFactory typeFactory;
 
-  public JdbcImplementor(SqlDialect dialect, JavaTypeFactory typeFactory,
+  JdbcImplementor(SqlDialect dialect, JavaTypeFactory typeFactory,
       JdbcCorrelationDataContextBuilder dataContextBuilder) {
     super(dialect);
-    this. typeFactory = typeFactory;
+    this.typeFactory = typeFactory;
     this.dataContextBuilder = dataContextBuilder;
   }
 
diff --git a/core/src/main/java/org/apache/calcite/rel/rel2sql/SqlImplementor.java b/core/src/main/java/org/apache/calcite/rel/rel2sql/SqlImplementor.java
index 40a10e9cf16..470c9ada2e4 100644
--- a/core/src/main/java/org/apache/calcite/rel/rel2sql/SqlImplementor.java
+++ b/core/src/main/java/org/apache/calcite/rel/rel2sql/SqlImplementor.java
@@ -16,6 +16,7 @@
  */
 package org.apache.calcite.rel.rel2sql;
 
+import org.apache.calcite.adapter.jdbc.JdbcCorrelationDataContext;
 import org.apache.calcite.config.CalciteSystemProperty;
 import org.apache.calcite.linq4j.Ord;
 import org.apache.calcite.linq4j.tree.Expressions;
@@ -767,6 +768,11 @@ public SqlNode toSql(@Nullable RexProgram program, RexNode rex) {
 
       case DYNAMIC_PARAM:
         final RexDynamicParam caseParam = (RexDynamicParam) rex;
+        if (caseParam.getIndex() >= JdbcCorrelationDataContext.OFFSET) {
+          throw new AssertionError("More than "
+              + JdbcCorrelationDataContext.OFFSET
+              + " dynamic parameters used in query");
+        }
         return new SqlDynamicParam(caseParam.getIndex(), POS);
 
       case IN: