Package org.elasticsearch.xpack.esql.datasources

Class DeclaredSchemaResolver

java.lang.Object

org.elasticsearch.xpack.esql.datasources.DeclaredSchemaResolver

public final class DeclaredSchemaResolver
extends Object

Bridges a DatasetMapping (the String-typed, server-side declaration) into the ES|QL currency the external-source resolver speaks: Attributes typed with DataType, plus the logical→physical rename map. This is the one place the declared type String becomes a DataType; everything downstream (planner, reader, output) sees logical names only.

Used by the resolver for both supply modes: in strict mode (dynamic: false) declaredAttributes(org.elasticsearch.cluster.metadata.DatasetMapping) is the entire resolved schema (no file is read); in non-strict mode the declared attributes overlay (and beat) the inferred ones of the same column. The renameMap(org.elasticsearch.cluster.metadata.DatasetMapping) rides the typed DeclaredReadSpec to the data node and is consumed at the reader-facing boundaries via PhysicalNames; ColumnMapping/reconciliation stay in logical space. It carries only renamed columns.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	DeclaredSchemaResolver.Overlaid	Result of a non-strict overlay: the user-facing output (declared columns renamed to their logical name and retyped, undeclared columns untouched) and the per-file fileSchema the reader resolves against the file.

Method Summary

Modifier and Type	Method	Description
static List<Attribute>	declaredAttributes(DatasetMapping mapping)	The declared columns as ES|QL attributes, keyed by logical name and in declaration order.
static DeclaredSchemaResolver.Overlaid	overlayNonStrict(List<Attribute> inferred, DatasetMapping mapping)	Apply a non-strict (dynamic: true) mapping over an inferred schema: every declared column overrides the inferred column of the same physical name — renamed to its logical name and pinned to its declared type — while undeclared inferred columns pass through unchanged.
static DeclaredSchemaResolver.Overlaid	overlayNonStrict(List<Attribute> inferred, DatasetMapping mapping, boolean lenient)	As overlayNonStrict(List, DatasetMapping) but lenient controls the unmatched-declared-column policy: strict (false) errors when a declared column is absent from inferred (used against the unified schema, where every declared column must appear); lenient (true) skips it (used per-file, where a column may legitimately be absent from one file under union-by-name).
static Map<String,String>	renameMap(DatasetMapping mapping)	Logical→physical name map for the columns that declare a path move (logical name ≠ physical name).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

declaredAttributes

public static List<Attribute> declaredAttributes(DatasetMapping mapping)

The declared columns as ES|QL attributes, keyed by logical name and in declaration order. Returns an empty list when there is no mappings block (an _id-only mappings block contributes no columns).

renameMap

public static Map<String,String> renameMap(DatasetMapping mapping)

Logical→physical name map for the columns that declare a path move (logical name ≠ physical name). Empty when nothing renames. The map is 1:1 (a physical is claimed by at most one logical — validation enforces it), so its PhysicalNames.inverse(java.util.Map<java.lang.String, java.lang.String>) is well-defined. PhysicalNames uses this at the last-mile reader-facing boundaries; the reader and ColumnMapping stay rename-agnostic.

overlayNonStrict

public static DeclaredSchemaResolver.Overlaid overlayNonStrict(List<Attribute> inferred,
 DatasetMapping mapping)

Apply a non-strict (dynamic: true) mapping over an inferred schema: every declared column overrides the inferred column of the same physical name — renamed to its logical name and pinned to its declared type — while undeclared inferred columns pass through unchanged. A declared column whose physical name is absent from the inferred schema is an error (it references a column the source does not have).

overlayNonStrict

public static DeclaredSchemaResolver.Overlaid overlayNonStrict(List<Attribute> inferred,
 DatasetMapping mapping,
 boolean lenient)

As overlayNonStrict(List, DatasetMapping) but lenient controls the unmatched-declared-column policy: strict (false) errors when a declared column is absent from inferred (used against the unified schema, where every declared column must appear); lenient (true) skips it (used per-file, where a column may legitimately be absent from one file under union-by-name).