public PlanOptimizers(
Metadata metadata,
SqlParser sqlParser,
FeaturesConfig featuresConfig,
boolean forceSingleNode) {
ImmutableList.Builder<PlanOptimizer> builder = ImmutableList.builder();
builder.add(
new DesugaringOptimizer(
metadata,
sqlParser), // Clean up all the sugar in expressions, e.g. AtTimeZone, must be run
// before all the other optimizers
new CanonicalizeExpressions(),
new ImplementFilteredAggregations(),
new ImplementSampleAsFilter(),
new SimplifyExpressions(metadata, sqlParser),
new UnaliasSymbolReferences(),
new PruneIdentityProjections(),
new SetFlatteningOptimizer(),
new ImplementIntersectAndExceptAsUnion(),
new LimitPushDown(), // Run the LimitPushDown after flattening set operators to make it
// easier to do the set flattening
new PruneUnreferencedOutputs(),
new MergeProjections(),
new TransformExistsApplyToScalarApply(metadata),
new TransformQuantifiedComparisonApplyToScalarApply(metadata),
new RemoveUnreferencedScalarInputApplyNodes(),
new TransformUncorrelatedInPredicateSubqueryToSemiJoin(),
new TransformUncorrelatedScalarToJoin(),
new TransformCorrelatedScalarAggregationToJoin(metadata),
new PredicatePushDown(metadata, sqlParser),
new MergeProjections(),
new SimplifyExpressions(
metadata,
sqlParser), // Re-run the SimplifyExpressions to simplify any recomposed expressions
// from other optimizations
new ProjectionPushDown(),
new UnaliasSymbolReferences(), // Run again because predicate pushdown and projection
// pushdown might add more projections
new PruneUnreferencedOutputs(), // Make sure to run this before index join. Filtered
// projections may not have all the columns.
new IndexJoinOptimizer(
metadata), // Run this after projections and filters have been fully simplified and
// pushed down
new CountConstantOptimizer(),
new WindowFilterPushDown(
metadata), // This must run after PredicatePushDown and LimitPushDown so that it
// squashes any successive filter nodes and limits
new MergeWindows(),
new ReorderWindows(), // Should be after MergeWindows to avoid unnecessary reordering of
// mergeable windows
new MergeProjections(),
new PruneUnreferencedOutputs(), // Make sure to run this at the end to help clean the plan
// for logging/execution and not remove info that other
// optimizers might need at an earlier point
new PruneIdentityProjections(), // This MUST run after PruneUnreferencedOutputs as it may
// introduce new redundant projections
new MetadataQueryOptimizer(metadata),
new EliminateCrossJoins(), // This can pull up Filter and Project nodes from between Joins,
// so we need to push them down again
new PredicatePushDown(metadata, sqlParser),
new ProjectionPushDown());
if (featuresConfig.isOptimizeSingleDistinct()) {
builder.add(new SingleDistinctOptimizer());
builder.add(new PruneUnreferencedOutputs());
}
builder.add(new OptimizeMixedDistinctAggregations(metadata));
if (!forceSingleNode) {
builder.add(new PushTableWriteThroughUnion()); // Must run before AddExchanges
builder.add(new AddExchanges(metadata, sqlParser));
}
builder.add(new PickLayout(metadata));
builder.add(new EmptyDeleteOptimizer()); // Run after table scan is removed by PickLayout
builder.add(
new PredicatePushDown(
metadata,
sqlParser)); // Run predicate push down one more time in case we can leverage new
// information from layouts' effective predicate
builder.add(new ProjectionPushDown());
builder.add(new MergeProjections());
builder.add(
new UnaliasSymbolReferences()); // Run unalias after merging projections to simplify
// projections more efficiently
builder.add(new PruneUnreferencedOutputs());
builder.add(new PruneIdentityProjections());
// Optimizers above this don't understand local exchanges, so be careful moving this.
builder.add(new AddLocalExchanges(metadata, sqlParser));
// Optimizers above this do not need to care about aggregations with the type other than SINGLE
// This optimizer must be run after all exchange-related optimizers
builder.add(new PartialAggregationPushDown(metadata.getFunctionRegistry()));
builder.add(new PruneIdentityProjections());
// DO NOT add optimizers that change the plan shape (computations) after this point
// Precomputed hashes - this assumes that partitioning will not change
builder.add(new HashGenerationOptimizer());
builder.add(new MetadataDeleteOptimizer(metadata));
builder.add(new BeginTableWrite(metadata)); // HACK! see comments in BeginTableWrite
// TODO: consider adding a formal final plan sanitization optimizer that prepares the plan for
// transmission/execution/logging
// TODO: figure out how to improve the set flattening optimizer so that it can run at any point
this.optimizers = builder.build();
}
