SQL: add support for index aliases for SYS COLUMNS command

x-pack/plugin/sql/qa/single-node/src/test/java/org/elasticsearch/xpack/sql/qa/single_node/SysColumnsIT.java

@@ -0,0 +1,13 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+package org.elasticsearch.xpack.sql.qa.single_node;
+
+import org.elasticsearch.xpack.sql.qa.jdbc.SysColumnsTestCase;
+
+public class SysColumnsIT extends SysColumnsTestCase {
+
+}

x-pack/plugin/sql/src/main/java/org/elasticsearch/xpack/sql/type/InvalidMappedField.java

@@ -7,6 +7,7 @@
 package org.elasticsearch.xpack.sql.type;
 
 import org.elasticsearch.xpack.sql.SqlIllegalArgumentException;
+import org.elasticsearch.xpack.sql.util.StringUtils;
 
 import java.util.Objects;
 
@@ -25,6 +26,11 @@ public InvalidMappedField(String name, String errorMessage) {
         this.errorMessage = errorMessage;
     }
 
+    public InvalidMappedField(String name) {
+        super(name, DataType.UNSUPPORTED, emptyMap(), false);
+        this.errorMessage = StringUtils.EMPTY;
+    }
+
     public String errorMessage() {
         return errorMessage;
     }

x-pack/plugin/sql/src/main/java/org/elasticsearch/xpack/sql/util/CollectionUtils.java

@@ -72,4 +72,11 @@ public static <T> List<T> combine(Collection<? extends T> left, T... entries) {
         }
         return list;
     }
+
+    public static int mapSize(int size) {
+        if (size < 2) {
+            return size + 1;
+        }
+        return (int) (size / 0.75f + 1f);
+    }
 }

x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/analysis/index/IndexResolverTests.java

@@ -315,8 +315,8 @@ public static IndexResolution merge(EsIndex... indices) {
     }
 
     public static List<EsIndex> separate(EsIndex... indices) {
-        return IndexResolver.separateMappings("*", null, Stream.of(indices).map(EsIndex::name).toArray(String[]::new),
-                fromMappings(indices));
+        return IndexResolver.separateMappings(null, Stream.of(indices).map(EsIndex::name).toArray(String[]::new),
+                fromMappings(indices), null);
     }
 
     public static Map<String, Map<String, FieldCapabilities>> fromMappings(EsIndex... indices) {