ESQL: Remove qualifier from attrs (elastic#110581)

In ES|QL's analyzer, we resolve names to field attributes, like some_field in FROM some_idx | KEEP some_field. The Attribute class, being copied from (S)QL, has a name and a qualified name, e.g. some_field and qualifier.some_field.

However, we never use the qualifier, so remove it.

Author: alex-spies

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/expression/Alias.java

@@ -16,7 +16,6 @@
 
 import java.io.IOException;
 import java.util.List;
-import java.util.Objects;
 
 import static java.util.Collections.singletonList;
 
@@ -32,7 +31,6 @@ public final class Alias extends NamedExpression {
     public static final NamedWriteableRegistry.Entry ENTRY = new NamedWriteableRegistry.Entry(NamedExpression.class, "Alias", Alias::new);
 
     private final Expression child;
-    private final String qualifier;
 
     /**
      * Postpone attribute creation until it is actually created.
@@ -41,21 +39,24 @@ public final class Alias extends NamedExpression {
     private Attribute lazyAttribute;
 
     public Alias(Source source, String name, Expression child) {
-        this(source, name, null, child, null);
+        this(source, name, child, null);
     }
 
-    public Alias(Source source, String name, String qualifier, Expression child) {
-        this(source, name, qualifier, child, null);
+    public Alias(Source source, String name, Expression child, NameId id) {
+        this(source, name, child, id, false);
     }
 
-    public Alias(Source source, String name, String qualifier, Expression child, NameId id) {
-        this(source, name, qualifier, child, id, false);
-    }
-
-    public Alias(Source source, String name, String qualifier, Expression child, NameId id, boolean synthetic) {
+    public Alias(Source source, String name, Expression child, NameId id, boolean synthetic) {
         super(source, name, singletonList(child), id, synthetic);
         this.child = child;
-        this.qualifier = qualifier;
+    }
+
+    @Deprecated
+    /**
+     * Old constructor from when this had a qualifier string. Still needed to not break serialization.
+     */
+    private Alias(Source source, String name, String qualifier, Expression child, NameId id, boolean synthetic) {
+        this(source, name, child, id, synthetic);
     }
 
     public Alias(StreamInput in) throws IOException {
@@ -73,7 +74,8 @@ public Alias(StreamInput in) throws IOException {
     public void writeTo(StreamOutput out) throws IOException {
         Source.EMPTY.writeTo(out);
         out.writeString(name());
-        out.writeOptionalString(qualifier());
+        // We used to write the qualifier here. We can still do if needed in the future.
+        out.writeOptionalString(null);
         out.writeNamedWriteable(child());
         id().writeTo(out);
         out.writeBoolean(synthetic());
@@ -86,30 +88,22 @@ public String getWriteableName() {
 
     @Override
     protected NodeInfo<Alias> info() {
-        return NodeInfo.create(this, Alias::new, name(), qualifier, child, id(), synthetic());
+        return NodeInfo.create(this, Alias::new, name(), child, id(), synthetic());
     }
 
     public Alias replaceChild(Expression child) {
-        return new Alias(source(), name(), qualifier, child, id(), synthetic());
+        return new Alias(source(), name(), child, id(), synthetic());
     }
 
     @Override
     public Alias replaceChildren(List<Expression> newChildren) {
-        return new Alias(source(), name(), qualifier, newChildren.get(0), id(), synthetic());
+        return new Alias(source(), name(), newChildren.get(0), id(), synthetic());
     }
 
     public Expression child() {
         return child;
     }
 
-    public String qualifier() {
-        return qualifier;
-    }
-
-    public String qualifiedName() {
-        return qualifier == null ? name() : qualifier + "." + name();
-    }
-
     @Override
     public Nullability nullable() {
         return child.nullable();
@@ -124,8 +118,8 @@ public DataType dataType() {
     public Attribute toAttribute() {
         if (lazyAttribute == null) {
             lazyAttribute = resolved()
-                ? new ReferenceAttribute(source(), name(), dataType(), qualifier, nullable(), id(), synthetic())
-                : new UnresolvedAttribute(source(), name(), qualifier);
+                ? new ReferenceAttribute(source(), name(), dataType(), nullable(), id(), synthetic())
+                : new UnresolvedAttribute(source(), name());
         }
         return lazyAttribute;
     }
@@ -146,18 +140,4 @@ public String nodeString() {
     public static Expression unwrap(Expression e) {
         return e instanceof Alias as ? as.child() : e;
     }
-
-    @Override
-    public boolean equals(Object obj) {
-        if (super.equals(obj) == false) {
-            return false;
-        }
-        Alias other = (Alias) obj;
-        return Objects.equals(qualifier, other.qualifier);
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(super.hashCode(), qualifier);
-    }
 }

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/expression/Attribute.java

@@ -7,15 +7,13 @@
 package org.elasticsearch.xpack.esql.core.expression;
 
 import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
-import org.elasticsearch.core.Tuple;
 import org.elasticsearch.xpack.esql.core.tree.Source;
 import org.elasticsearch.xpack.esql.core.type.DataType;
 
 import java.util.List;
 import java.util.Objects;
 
 import static java.util.Collections.emptyList;
-import static org.elasticsearch.xpack.esql.core.util.StringUtils.splitQualifiedIndex;
 
 /**
  * {@link Expression}s that can be materialized and describe properties of the derived table.
@@ -35,33 +33,19 @@ public static List<NamedWriteableRegistry.Entry> getNamedWriteables() {
         return List.of(FieldAttribute.ENTRY, MetadataAttribute.ENTRY, ReferenceAttribute.ENTRY);
     }
 
-    // empty - such as a top level attribute in SELECT cause
-    // present - table name or a table name alias
-    private final String qualifier;
-    // cluster name in the qualifier (if any)
-    private final String cluster;
-
     // can the attr be null - typically used in JOINs
     private final Nullability nullability;
 
-    public Attribute(Source source, String name, String qualifier, NameId id) {
-        this(source, name, qualifier, Nullability.TRUE, id);
+    public Attribute(Source source, String name, NameId id) {
+        this(source, name, Nullability.TRUE, id);
     }
 
-    public Attribute(Source source, String name, String qualifier, Nullability nullability, NameId id) {
-        this(source, name, qualifier, nullability, id, false);
+    public Attribute(Source source, String name, Nullability nullability, NameId id) {
+        this(source, name, nullability, id, false);
     }
 
-    public Attribute(Source source, String name, String qualifier, Nullability nullability, NameId id, boolean synthetic) {
+    public Attribute(Source source, String name, Nullability nullability, NameId id, boolean synthetic) {
         super(source, name, emptyList(), id, synthetic);
-        if (qualifier != null) {
-            Tuple<String, String> splitQualifier = splitQualifiedIndex(qualifier);
-            this.cluster = splitQualifier.v1();
-            this.qualifier = splitQualifier.v2();
-        } else {
-            this.cluster = null;
-            this.qualifier = null;
-        }
         this.nullability = nullability;
     }
 
@@ -70,14 +54,6 @@ public final Expression replaceChildren(List<Expression> newChildren) {
         throw new UnsupportedOperationException("this type of node doesn't have any children to replace");
     }
 
-    public String qualifier() {
-        return qualifier;
-    }
-
-    public String qualifiedName() {
-        return qualifier == null ? name() : qualifier + "." + name();
-    }
-
     @Override
     public Nullability nullable() {
         return nullability;
@@ -89,42 +65,26 @@ public AttributeSet references() {
     }
 
     public Attribute withLocation(Source source) {
-        return Objects.equals(source(), source) ? this : clone(source, name(), dataType(), qualifier(), nullable(), id(), synthetic());
-    }
-
-    public Attribute withQualifier(String qualifier) {
-        return Objects.equals(qualifier(), qualifier)
-            ? this
-            : clone(source(), name(), dataType(), qualifier, nullable(), id(), synthetic());
+        return Objects.equals(source(), source) ? this : clone(source, name(), dataType(), nullable(), id(), synthetic());
     }
 
     public Attribute withName(String name) {
-        return Objects.equals(name(), name) ? this : clone(source(), name, dataType(), qualifier(), nullable(), id(), synthetic());
+        return Objects.equals(name(), name) ? this : clone(source(), name, dataType(), nullable(), id(), synthetic());
     }
 
     public Attribute withNullability(Nullability nullability) {
-        return Objects.equals(nullable(), nullability)
-            ? this
-            : clone(source(), name(), dataType(), qualifier(), nullability, id(), synthetic());
+        return Objects.equals(nullable(), nullability) ? this : clone(source(), name(), dataType(), nullability, id(), synthetic());
     }
 
     public Attribute withId(NameId id) {
-        return clone(source(), name(), dataType(), qualifier(), nullable(), id, synthetic());
+        return clone(source(), name(), dataType(), nullable(), id, synthetic());
     }
 
     public Attribute withDataType(DataType type) {
-        return Objects.equals(dataType(), type) ? this : clone(source(), name(), type, qualifier(), nullable(), id(), synthetic());
+        return Objects.equals(dataType(), type) ? this : clone(source(), name(), type, nullable(), id(), synthetic());
     }
 
-    protected abstract Attribute clone(
-        Source source,
-        String name,
-        DataType type,
-        String qualifier,
-        Nullability nullability,
-        NameId id,
-        boolean synthetic
-    );
+    protected abstract Attribute clone(Source source, String name, DataType type, Nullability nullability, NameId id, boolean synthetic);
 
     @Override
     public Attribute toAttribute() {
@@ -143,27 +103,27 @@ public boolean semanticEquals(Expression other) {
 
     @Override
     protected Expression canonicalize() {
-        return clone(Source.EMPTY, name(), dataType(), qualifier, nullability, id(), synthetic());
+        return clone(Source.EMPTY, name(), dataType(), nullability, id(), synthetic());
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(super.hashCode(), qualifier, nullability);
+        return Objects.hash(super.hashCode(), nullability);
     }
 
     @Override
     public boolean equals(Object obj) {
         if (super.equals(obj)) {
             Attribute other = (Attribute) obj;
-            return Objects.equals(qualifier, other.qualifier) && Objects.equals(nullability, other.nullability);
+            return Objects.equals(nullability, other.nullability);
         }
 
         return false;
     }
 
     @Override
     public String toString() {
-        return qualifiedName() + "{" + label() + "}" + "#" + id();
+        return name() + "{" + label() + "}" + "#" + id();
     }
 
     @Override

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/expression/EmptyAttribute.java

@@ -21,7 +21,7 @@
  */
 public class EmptyAttribute extends Attribute {
     public EmptyAttribute(Source source) {
-        super(source, StringUtils.EMPTY, null, null);
+        super(source, StringUtils.EMPTY, null);
     }
 
     @Override
@@ -35,15 +35,7 @@ public String getWriteableName() {
     }
 
     @Override
-    protected Attribute clone(
-        Source source,
-        String name,
-        DataType type,
-        String qualifier,
-        Nullability nullability,
-        NameId id,
-        boolean synthetic
-    ) {
+    protected Attribute clone(Source source, String name, DataType type, Nullability nullability, NameId id, boolean synthetic) {
         return this;
     }