Decimal literal should convert to double in pushdown

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

Author: LantaoJin

integ-test/src/yamlRestTest/resources/rest-api-spec/test/issues/3810.yml

@@ -0,0 +1,38 @@
+setup:
+  - do:
+      query.settings:
+        body:
+          transient:
+            plugins.calcite.enabled : true
+            plugins.calcite.fallback.allowed : false
+
+---
+teardown:
+  - do:
+      query.settings:
+        body:
+          transient:
+            plugins.calcite.enabled : false
+            plugins.calcite.fallback.allowed : true
+
+---
+"Decimal literal should convert to double in pushdown":
+  - skip:
+      features:
+        - headers
+  - do:
+      bulk:
+        index: test
+        refresh: true
+        body:
+          - '{"index": {}}'
+          - '{"balance": 1000.0}'
+  - do:
+      headers:
+        Content-Type: 'application/json'
+      ppl:
+        body:
+          query: 'source=test | where balance >= 1000.0 | stats avg(balance)'
+  - match: {"total": 1}
+  - match: {"schema": [{"name": "avg(balance)", "type": "double"}]}
+  - match: {"datarows": [[1000.0]]}

opensearch/src/main/java/org/opensearch/sql/opensearch/request/PredicateAnalyzer.java

@@ -1057,7 +1057,7 @@ Object value() {
         return sargValue();
       } else if (isIntegral()) {
         return longValue();
-      } else if (isFloatingPoint()) {
+      } else if (isFractional()) {
         return doubleValue();
       } else if (isBoolean()) {
         return booleanValue();
@@ -1072,8 +1072,8 @@ boolean isIntegral() {
       return SqlTypeName.INT_TYPES.contains(literal.getType().getSqlTypeName());
     }
 
-    boolean isFloatingPoint() {
-      return SqlTypeName.APPROX_TYPES.contains(literal.getType().getSqlTypeName());
+    boolean isFractional() {
+      return SqlTypeName.FRACTIONAL_TYPES.contains(literal.getType().getSqlTypeName());
     }
 
     boolean isBoolean() {