Fix IT

Signed-off-by: Lantao Jin <ltjin@amazon.com>

Author: LantaoJin

core/src/main/java/org/opensearch/sql/calcite/ExtendedRexBuilder.java

@@ -40,6 +40,11 @@ public static int getNextId() {
     return threadCounter.get().getAndIncrement();
   }
 
+  // For test only. Reset id to avoid unstable explain output of query.
+  public static void resetId() {
+    threadCounter.get().set(0);
+  }
+
   public ExtendedRexBuilder(RexBuilder rexBuilder) {
     super(rexBuilder.getTypeFactory());
   }

integ-test/src/test/java/org/opensearch/sql/calcite/remote/CalciteExplainIT.java

@@ -11,6 +11,7 @@
 import org.junit.Assume;
 import org.junit.Ignore;
 import org.junit.Test;
+import org.opensearch.sql.calcite.ExtendedRexBuilder;
 import org.opensearch.sql.ppl.ExplainIT;
 
 public class CalciteExplainIT extends ExplainIT {
@@ -19,6 +20,7 @@ public void init() throws Exception {
     super.init();
     enableCalcite();
     disallowCalciteFallback();
+    ExtendedRexBuilder.resetId();
   }
 
   @Override