add IT in explain

Signed-off-by: xinyual <xinyual@amazon.com>

Author: xinyual

integ-test/src/test/java/org/opensearch/sql/ppl/ExplainIT.java

@@ -19,6 +19,7 @@ public class ExplainIT extends PPLIntegTestCase {
   public void init() throws Exception {
     super.init();
     loadIndex(Index.ACCOUNT);
+    loadIndex(Index.BANK);
   }
 
   @Test
@@ -57,6 +58,21 @@ public void testFilterPushDownExplain() throws IOException {
                 + "| fields age"));
   }
 
+  @Test
+  public void testFilterByCompareStringTimestampPushDownExplain() throws IOException {
+    String expected =
+            isCalciteEnabled()
+                    ? loadFromFile("expectedOutput/calcite/explain_filter_push_compare_timestamp_string.json")
+                    : loadFromFile("expectedOutput/ppl/explain_filter_push_compare_timestamp_string.json");
+
+    assertJsonEqualsIgnoreId(
+            expected,
+            explainQueryToString(
+                    "source=opensearch-sql_test_index_bank"
+                    + "| where birthdate > '2016-12-08 00:00:00' "
+                    + "| where birthdate < '2018-11-09 00:00:00' "));
+  }
+
   @Test
   public void testFilterAndAggPushDownExplain() throws IOException {
     String expected =

integ-test/src/test/resources/expectedOutput/calcite/explain_filter_push_compare_timestamp_string.json

@@ -0,0 +1,6 @@
+{
+  "calcite" : {
+    "logical" : "LogicalProject(account_number=[$0], firstname=[$1], address=[$2], birthdate=[$3], gender=[$4], city=[$5], lastname=[$6], balance=[$7], employer=[$8], state=[$9], age=[$10], email=[$11], male=[$12])\n  LogicalFilter(condition=[<($3, TIMESTAMP('2018-11-09 00:00:00':VARCHAR))])\n    LogicalFilter(condition=[>($3, TIMESTAMP('2016-12-08 00:00:00':VARCHAR))])\n      CalciteLogicalIndexScan(table=[[OpenSearch, opensearch-sql_test_index_bank]])\n",
+    "physical" : "CalciteEnumerableIndexScan(table=[[OpenSearch, opensearch-sql_test_index_bank]], PushDownContext=[[PROJECT->[account_number, firstname, address, birthdate, gender, city, lastname, balance, employer, state, age, email, male], FILTER->>($3, '2016-12-08 00:00:00'), FILTER-><($3, '2018-11-09 00:00:00')], OpenSearchRequestBuilder(sourceBuilder={\"from\":0,\"timeout\":\"1m\",\"query\":{\"bool\":{\"filter\":[{\"range\":{\"birthdate\":{\"from\":\"2016-12-08T00:00:00.000Z\",\"to\":null,\"include_lower\":false,\"include_upper\":true,\"boost\":1.0}}},{\"range\":{\"birthdate\":{\"from\":null,\"to\":\"2018-11-09T00:00:00.000Z\",\"include_lower\":true,\"include_upper\":false,\"boost\":1.0}}}],\"adjust_pure_negative\":true,\"boost\":1.0}},\"_source\":{\"includes\":[\"account_number\",\"firstname\",\"address\",\"birthdate\",\"gender\",\"city\",\"lastname\",\"balance\",\"employer\",\"state\",\"age\",\"email\",\"male\"],\"excludes\":[]},\"sort\":[{\"_doc\":{\"order\":\"asc\"}}]}, requestedTotalSize=2147483647, pageSize=null, startFrom=0)])\n"
+  }
+}

integ-test/src/test/resources/expectedOutput/ppl/explain_filter_push_compare_timestamp_string.json

@@ -0,0 +1,15 @@
+{
+  "root" : {
+    "name" : "ProjectOperator",
+    "description" : {
+      "fields" : "[account_number, firstname, address, birthdate, gender, city, lastname, balance, employer, state, age, email, male]"
+    },
+    "children" : [ {
+      "name" : "OpenSearchIndexScan",
+      "description" : {
+        "request" : "OpenSearchQueryRequest(indexName=opensearch-sql_test_index_bank, sourceBuilder={\"from\":0,\"size\":10000,\"timeout\":\"1m\",\"query\":{\"bool\":{\"filter\":[{\"range\":{\"birthdate\":{\"from\":null,\"to\":1541721600000,\"include_lower\":true,\"include_upper\":false,\"boost\":1.0}}},{\"range\":{\"birthdate\":{\"from\":1481155200000,\"to\":null,\"include_lower\":false,\"include_upper\":true,\"boost\":1.0}}}],\"adjust_pure_negative\":true,\"boost\":1.0}},\"_source\":{\"includes\":[\"account_number\",\"firstname\",\"address\",\"birthdate\",\"gender\",\"city\",\"lastname\",\"balance\",\"employer\",\"state\",\"age\",\"email\",\"male\"],\"excludes\":[]},\"sort\":[{\"_doc\":{\"order\":\"asc\"}}]}, needClean=true, searchDone=false, pitId=s9y3QQEeb3BlbnNlYXJjaC1zcWxfdGVzdF9pbmRleF9iYW5rFmtHVFBVZFdaVEVTdzh4ZFVDYlFiU2cAFk8tSmZBa2hpUXRHOEFVTGdnMmxYUncAAAAAAAAAAAEWOFZwckxjWGhUaXVYRVBRWXptNFlQdwEWa0dUUFVkV1pURVN3OHhkVUNiUWJTZwAA, cursorKeepAlive=1m, searchAfter=null, searchResponse=null)"
+      },
+      "children" : [ ]
+    } ]
+  }
+}