Address comments

x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/querydsl/container/SearchHitFieldRef.java

@@ -12,7 +12,6 @@
 import org.elasticsearch.xpack.ql.type.DataType;
 
 import static org.elasticsearch.xpack.ql.type.DataTypes.DATETIME;
-import static org.elasticsearch.xpack.ql.type.DataTypes.KEYWORD;
 
 // NB: this class is taken from SQL - it hasn't been ported over to QL
 // since at this stage is unclear whether the whole FieldExtraction infrastructure
@@ -64,10 +63,6 @@ public String toString() {
         return name;
     }
 
-    private static boolean hasDocValues(DataType dataType) {
-        return dataType == KEYWORD || dataType == DATETIME;
-    }
-
     private static String format(DataType dataType) {
         // We need epoch_millis for the tiebreaker timestamp field, because parsing timestamp strings
         // can have a negative performance impact

x-pack/plugin/sql/src/main/java/org/elasticsearch/xpack/sql/querydsl/container/QueryContainer.java

@@ -336,8 +336,7 @@ private FieldExtraction topHitFieldRef(FieldAttribute fieldAttr) {
             fullFieldName.insert(0, ".").insert(0, rootField.parent().field().getName());
             rootField = rootField.parent();
         }
-        return new SearchHitFieldRef(aliasName(actualField), fullFieldName.toString(), fieldAttr.field().getDataType(),
-                fieldAttr.field().isAggregatable(), fieldAttr.field().isAlias());
+        return new SearchHitFieldRef(aliasName(actualField), fieldAttr.field().getDataType());
     }
 
     private Tuple<QueryContainer, FieldExtraction> nestedHitFieldRef(FieldAttribute attr) {
@@ -347,8 +346,7 @@ private Tuple<QueryContainer, FieldExtraction> nestedHitFieldRef(FieldAttribute
                 SqlDataTypes.format(attr.field().getDataType()),
                 SqlDataTypes.isFromDocValuesOnly(attr.field().getDataType()));
 
-        SearchHitFieldRef nestedFieldRef = new SearchHitFieldRef(name, null, attr.field().getDataType(), attr.field().isAggregatable(),
-                false, attr.parent().name());
+        SearchHitFieldRef nestedFieldRef = new SearchHitFieldRef(name, attr.field().getDataType(), attr.parent().name());
 
         return new Tuple<>(
                 new QueryContainer(q, aggs, fields, aliases, pseudoFunctions, scalarFunctions, sort, limit, trackHits, includeFrozen,

x-pack/plugin/sql/src/main/java/org/elasticsearch/xpack/sql/querydsl/container/SearchHitFieldRef.java

@@ -12,24 +12,16 @@
 
 public class SearchHitFieldRef extends FieldReference {
     private final String name;
-    private final String fullFieldName; // path included. If field full path is a.b.c, full field name is "a.b.c" and name is "c"
     private final DataType dataType;
-    private final boolean docValue;
     private final String hitName;
 
-    public SearchHitFieldRef(String name, String fullFieldName, DataType dataType, boolean useDocValueInsteadOfSource, boolean isAlias) {
-        this(name, fullFieldName, dataType, useDocValueInsteadOfSource, isAlias, null);
+    public SearchHitFieldRef(String name, DataType dataType) {
+        this(name, dataType, null);
     }
 
-    public SearchHitFieldRef(String name, String fullFieldName, DataType dataType, boolean useDocValueInsteadOfSource, boolean isAlias,
-            String hitName) {
+    public SearchHitFieldRef(String name, DataType dataType, String hitName) {
         this.name = name;
-        this.fullFieldName = fullFieldName;
         this.dataType = dataType;
-        // these field types can only be extracted from docvalue_fields (ie, values already computed by Elasticsearch)
-        // because, for us to be able to extract them from _source, we would need the mapping of those fields (which we don't have)
-        this.docValue = isAlias ? useDocValueInsteadOfSource :
-            (SqlDataTypes.isFromDocValuesOnly(dataType) ? useDocValueInsteadOfSource : false);
         this.hitName = hitName;
     }
 
@@ -42,18 +34,10 @@ public String name() {
         return name;
     }
 
-    public String fullFieldName() {
-        return fullFieldName;
-    }
-
     public DataType getDataType() {
         return dataType;
     }
 
-    public boolean useDocValue() {
-        return docValue;
-    }
-
     @Override
     public void collectFields(QlSourceBuilder sourceBuilder) {
         // nested fields are handled by inner hits

x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/parser/ExpressionTests.java

@@ -304,11 +304,6 @@ public void testCastWithUnquotedDataType() {
         assertEquals(INTEGER, mul.dataType());
     }
 
-    public void testCastToDatetimeNanosNotSupported() {
-        ParsingException e = expectThrows(ParsingException.class, () -> parser.createExpression("CAST('foo' AS DATETIME_NANOS)"));
-        assertEquals("line 1:16: Does not recognize type [DATETIME_NANOS]", e.getMessage());
-    }
-
     public void testCastWithQuotedDataType() {
         Expression expr = parser.createExpression("CAST(10*2 AS \"LonG\")");
         assertEquals(Cast.class, expr.getClass());