Module com.darkcollective.relix.semantic

Package com.darkcollective.relix.semantic.internal

Class SchemaInference

java.lang.Object

com.darkcollective.relix.semantic.internal.SchemaInference

public final class SchemaInference
extends Object

Public facade for running schema inference over an arbitrary RelNode tree outside the full five-phase analysis pipeline.

This is primarily intended for consumers — such as the query optimizer and execution engine — that hold a tree which is not the one originally analysed (for example, a tree rewritten by optimization passes) and therefore has no entries in the original SemanticModel.nodeSchemas() map. Because SchemaAnnotations is keyed by object identity, a rewritten tree's nodes are unknown to the original annotation map and must be re-annotated before they can be executed.

Merging semantics

annotate(com.darkcollective.relix.symbol.table.SymbolTable, com.darkcollective.relix.ast.RelNode, com.darkcollective.relix.semantic.SchemaAnnotations, com.darkcollective.relix.function.FunctionCatalog) returns a fresh SchemaAnnotations seeded from the supplied base map and then augmented with annotations for root and all of its descendants. Existing entries are preserved: this matters when root contains RelationNode leaves that reference named views ( QueryRelationSymbols) whose own bodies were annotated during the original analysis but are not re-walked here.

Thread safety

Stateless; safe to call concurrently. Each call builds its own annotation map and visitor.

Method Summary

Modifier and Type	Method	Description
static SchemaAnnotations	annotate(SymbolTable symbolTable, RelNode root, SchemaAnnotations base, FunctionCatalog functions)	Returns a SchemaAnnotations containing every entry from base plus a freshly-inferred schema for root and each of its descendant nodes.

Methods inherited from class java.lang.Object

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

Method Details

annotate

public static SchemaAnnotations annotate(SymbolTable symbolTable,
 RelNode root,
 SchemaAnnotations base,
 FunctionCatalog functions)

Returns a SchemaAnnotations containing every entry from base plus a freshly-inferred schema for root and each of its descendant nodes.

The base map is not mutated. Inference errors are not surfaced: callers are expected to supply a tree derived from an already-valid model (e.g. an optimizer rewrite, which is semantics-preserving), so any node that cannot be resolved simply remains unannotated.

Parameters:

symbolTable - the symbol table used to resolve relation and function references; must not be null

root - the root of the tree to annotate; must not be null

base - annotations to seed the result with (typically the original SemanticModel.nodeSchemas()); must not be null

functions - the catalogue function calls in the tree are typed against — pass the one the tree was analysed with (SemanticModel.functions()), so a re-annotated tree types its calls exactly as the original did; must not be null

Returns:

a new annotation map covering base and root's subtree