Class QueryOptimizer

java.lang.Object

com.loomcache.server.query.QueryOptimizer

public class QueryOptimizer
extends Object

Query optimizer for the SQL query engine. Applies various optimization rules to query plans and maintains a plan cache.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	QueryOptimizer.ColumnPruning	Column pruning optimization: only loads columns needed by SELECT, WHERE, and ORDER BY.
static final class	QueryOptimizer.ConstantFolding	Constant folding optimization: evaluates constant expressions at compile time.
static final record	QueryOptimizer.CostEstimate	Cost estimate for a query plan.
static final class	QueryOptimizer.IndexSelection	Index selection optimization: chooses the best index for WHERE clause predicates.
static final class	QueryOptimizer.LimitPushDown	Limit push-down optimization: pushes LIMIT closer to the scan when possible.
static interface	QueryOptimizer.OptimizationRule	Sealed interface for optimization rules.
static final class	QueryOptimizer.OptimizedQueryPlan	Optimized query plan with metadata.
static final class	QueryOptimizer.PredicatePushDown	Predicate push-down optimization: moves predicates closer to the data source.
static final class	QueryOptimizer.QueryCostEstimator	Cost estimator for query execution.
static final class	QueryOptimizer.QueryPlanCache	LRU cache for parsed and optimized query plans.
static final record	QueryOptimizer.TableStatistics	Table statistics for cost estimation.

Constructor Summary

Constructors

Constructor	Description
QueryOptimizer()
QueryOptimizer(int cacheSize)

Method Summary

Modifier and Type	Method	Description
QueryOptimizer.QueryPlanCache	getCache()
QueryOptimizer.OptimizedQueryPlan	optimize(QueryPlan plan, @Nullable QueryOptimizer.TableStatistics stats, Map<String, MapIndex<?,?>> availableIndexes)	Optimizes a query plan.
static @Nullable Object	partitionKeyFor(Predicate predicate)	Finds an explicit partition-routing key embedded in a predicate tree.

Methods inherited from class Object

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

Constructor Details

QueryOptimizer

public QueryOptimizer()

QueryOptimizer

public QueryOptimizer(int cacheSize)

Method Details

partitionKeyFor

public static @Nullable Object partitionKeyFor(Predicate predicate)

Finds an explicit partition-routing key embedded in a predicate tree. Only AND composition preserves the guarantee that the partition constraint applies to every returned row; OR/NOT predicates must still scatter.

optimize

public QueryOptimizer.OptimizedQueryPlan optimize(QueryPlan plan,
 @Nullable QueryOptimizer.TableStatistics stats,
 Map<String, MapIndex<?,?>> availableIndexes)

Optimizes a query plan.

getCache

public QueryOptimizer.QueryPlanCache getCache()