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Exctract JOIN ON visitor from LogicalExpressionOptimizerVisitor
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vdimir
parent
05163be79c
commit
bdeb04f7d3
@ -16,6 +16,181 @@ namespace ErrorCodes
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extern const int LOGICAL_ERROR;
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}
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/// Visitor that optimizes logical expressions _only_ in JOIN ON section
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class JoinOnLogicalExpressionOptimizerVisitor : public InDepthQueryTreeVisitorWithContext<JoinOnLogicalExpressionOptimizerVisitor>
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{
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public:
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using Base = InDepthQueryTreeVisitorWithContext<JoinOnLogicalExpressionOptimizerVisitor>;
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explicit JoinOnLogicalExpressionOptimizerVisitor(ContextPtr context)
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: Base(std::move(context))
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{}
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void enterImpl(QueryTreeNodePtr & node)
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{
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auto * function_node = node->as<FunctionNode>();
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if (!function_node)
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return;
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if (function_node->getFunctionName() == "or")
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{
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tryOptimizeIsNotDistinctOrIsNull(node);
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return;
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}
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}
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private:
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void tryOptimizeIsNotDistinctOrIsNull(QueryTreeNodePtr & node)
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{
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auto & function_node = node->as<FunctionNode &>();
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assert(function_node.getFunctionName() == "or");
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QueryTreeNodes or_operands;
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/// Indices of `equals` or `isNotDistinctFrom` functions in the vector above
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std::vector<size_t> equals_functions_indices;
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/** Map from `isNull` argument to indices of operands that contains that `isNull` functions
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* `a = b OR (a IS NULL AND b IS NULL) OR (a IS NULL AND c IS NULL)`
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* will be mapped to
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* {
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* a => [(a IS NULL AND b IS NULL), (a IS NULL AND c IS NULL)]
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* b => [(a IS NULL AND b IS NULL)]
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* c => [(a IS NULL AND c IS NULL)]
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* }
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* Then for each a <=> b we can find all operands that contains both a IS NULL and b IS NULL
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*/
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QueryTreeNodePtrWithHashMap<std::vector<size_t>> is_null_argument_to_indices;
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for (const auto & argument : function_node.getArguments())
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{
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or_operands.push_back(argument);
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auto * argument_function = argument->as<FunctionNode>();
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if (!argument_function)
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continue;
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const auto & func_name = argument_function->getFunctionName();
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if (func_name == "equals" || func_name == "isNotDistinctFrom")
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equals_functions_indices.push_back(or_operands.size() - 1);
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if (func_name == "and")
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{
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for (const auto & and_argument : argument_function->getArguments().getNodes())
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{
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auto * and_argument_function = and_argument->as<FunctionNode>();
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if (and_argument_function && and_argument_function->getFunctionName() == "isNull")
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{
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const auto & is_null_argument = and_argument_function->getArguments().getNodes()[0];
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is_null_argument_to_indices[is_null_argument].push_back(or_operands.size() - 1);
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}
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}
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}
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}
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/// OR operands that are changed to and needs to be re-resolved
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std::unordered_set<size_t> arguments_to_reresolve;
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for (size_t equals_function_idx : equals_functions_indices)
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{
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auto * equals_function = or_operands[equals_function_idx]->as<FunctionNode>();
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/// For a <=> b we are looking for expressions containing both `a IS NULL` and `b IS NULL` combined with AND
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const auto & argument_nodes = equals_function->getArguments().getNodes();
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const auto & lhs_is_null_parents = is_null_argument_to_indices[argument_nodes[0]];
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const auto & rhs_is_null_parents = is_null_argument_to_indices[argument_nodes[1]];
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std::unordered_set<size_t> operands_to_optimize;
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std::set_intersection(lhs_is_null_parents.begin(), lhs_is_null_parents.end(),
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rhs_is_null_parents.begin(), rhs_is_null_parents.end(),
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std::inserter(operands_to_optimize, operands_to_optimize.begin()));
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/// If we have `a = b OR (a IS NULL AND b IS NULL)` we can optimize it to `a <=> b`
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if (!operands_to_optimize.empty() && equals_function->getFunctionName() == "equals")
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arguments_to_reresolve.insert(equals_function_idx);
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for (size_t to_optimize_idx : operands_to_optimize)
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{
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/// We are looking for operand `a IS NULL AND b IS NULL AND ...`
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auto * operand_to_optimize = or_operands[to_optimize_idx]->as<FunctionNode>();
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/// Remove `a IS NULL` and `b IS NULL` arguments from AND
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QueryTreeNodes new_arguments;
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for (const auto & and_argument : operand_to_optimize->getArguments().getNodes())
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{
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bool to_eliminate = false;
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const auto * and_argument_function = and_argument->as<FunctionNode>();
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if (and_argument_function && and_argument_function->getFunctionName() == "isNull")
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{
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const auto & is_null_argument = and_argument_function->getArguments().getNodes()[0];
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to_eliminate = (is_null_argument->isEqual(*argument_nodes[0]) || is_null_argument->isEqual(*argument_nodes[1]));
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}
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if (to_eliminate)
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arguments_to_reresolve.insert(to_optimize_idx);
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else
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new_arguments.emplace_back(and_argument);
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}
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/// If less than two arguments left, we will remove or replace the whole AND below
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operand_to_optimize->getArguments().getNodes() = std::move(new_arguments);
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}
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}
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if (arguments_to_reresolve.empty())
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/// Nothing have been changed
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return;
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auto and_function_resolver = FunctionFactory::instance().get("and", getContext());
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auto strict_equals_function_resolver = FunctionFactory::instance().get("isNotDistinctFrom", getContext());
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QueryTreeNodes new_or_operands;
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for (size_t i = 0; i < or_operands.size(); ++i)
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{
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if (arguments_to_reresolve.contains(i))
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{
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auto * function = or_operands[i]->as<FunctionNode>();
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if (function->getFunctionName() == "equals")
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{
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/// Because we removed checks for IS NULL, we should replace `a = b` with `a <=> b`
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function->resolveAsFunction(strict_equals_function_resolver);
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new_or_operands.emplace_back(std::move(or_operands[i]));
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}
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else if (function->getFunctionName() == "and")
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{
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const auto & and_arguments = function->getArguments().getNodes();
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if (and_arguments.size() > 1)
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{
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function->resolveAsFunction(and_function_resolver);
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new_or_operands.emplace_back(std::move(or_operands[i]));
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}
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else if (and_arguments.size() == 1)
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{
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/// Replace AND with a single argument with the argument itself
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new_or_operands.emplace_back(and_arguments[0]);
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}
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}
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else
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throw Exception(ErrorCodes::LOGICAL_ERROR, "Unexpected function name: '{}'", function->getFunctionName());
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}
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else
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{
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new_or_operands.emplace_back(std::move(or_operands[i]));
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}
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}
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if (new_or_operands.size() == 1)
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{
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node = std::move(new_or_operands[0]);
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return;
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}
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/// Rebuild OR function
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auto or_function_resolver = FunctionFactory::instance().get("or", getContext());
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function_node.getArguments().getNodes() = std::move(new_or_operands);
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function_node.resolveAsFunction(or_function_resolver);
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}
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};
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class LogicalExpressionOptimizerVisitor : public InDepthQueryTreeVisitorWithContext<LogicalExpressionOptimizerVisitor>
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{
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public:
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@ -29,13 +204,15 @@ public:
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{
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if (auto * join_node = node->as<JoinNode>())
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{
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join_stack.push_back(join_node);
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/// Operator <=> is not supported outside of JOIN ON section
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if (join_node->hasJoinExpression())
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{
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JoinOnLogicalExpressionOptimizerVisitor join_on_visitor(getContext());
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join_on_visitor.visit(join_node->getJoinExpression());
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}
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return;
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}
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if (!join_stack.empty() && join_stack.back()->getJoinExpression().get() == node.get())
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is_inside_on_section = true;
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auto * function_node = node->as<FunctionNode>();
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if (!function_node)
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@ -44,10 +221,6 @@ public:
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if (function_node->getFunctionName() == "or")
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{
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tryReplaceOrEqualsChainWithIn(node);
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/// Operator <=> is not supported outside of JOIN ON section
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if (is_inside_on_section)
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tryOptimizeIsNotDistinctOrIsNull(node);
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return;
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}
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@ -58,19 +231,6 @@ public:
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}
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}
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void leaveImpl(QueryTreeNodePtr & node)
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{
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if (!join_stack.empty() && join_stack.back()->getJoinExpression().get() == node.get())
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is_inside_on_section = false;
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if (auto * join_node = node->as<JoinNode>())
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{
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assert(join_stack.back() == join_node);
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join_stack.pop_back();
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return;
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}
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}
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private:
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void tryReplaceAndEqualsChainsWithConstant(QueryTreeNodePtr & node)
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{
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@ -264,159 +424,6 @@ private:
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function_node.getArguments().getNodes() = std::move(or_operands);
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function_node.resolveAsFunction(or_function_resolver);
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}
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void tryOptimizeIsNotDistinctOrIsNull(QueryTreeNodePtr & node)
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{
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auto & function_node = node->as<FunctionNode &>();
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assert(function_node.getFunctionName() == "or");
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QueryTreeNodes or_operands;
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/// Indices of `equals` or `isNotDistinctFrom` functions in the vector above
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std::vector<size_t> equals_functions_indices;
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/** Map from `isNull` argument to indices of operands that contains that `isNull` functions
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* `a = b OR (a IS NULL AND b IS NULL) OR (a IS NULL AND c IS NULL)`
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* will be mapped to
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* {
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* a => [(a IS NULL AND b IS NULL), (a IS NULL AND c IS NULL)]
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* b => [(a IS NULL AND b IS NULL)]
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* c => [(a IS NULL AND c IS NULL)]
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* }
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* Then for each a <=> b we can find all operands that contains both a IS NULL and b IS NULL
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*/
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QueryTreeNodePtrWithHashMap<std::vector<size_t>> is_null_argument_to_indices;
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for (const auto & argument : function_node.getArguments())
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{
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or_operands.push_back(argument);
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auto * argument_function = argument->as<FunctionNode>();
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if (!argument_function)
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continue;
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const auto & func_name = argument_function->getFunctionName();
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if (func_name == "equals" || func_name == "isNotDistinctFrom")
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equals_functions_indices.push_back(or_operands.size() - 1);
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if (func_name == "and")
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{
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for (const auto & and_argument : argument_function->getArguments().getNodes())
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{
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auto * and_argument_function = and_argument->as<FunctionNode>();
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if (and_argument_function && and_argument_function->getFunctionName() == "isNull")
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{
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const auto & is_null_argument = and_argument_function->getArguments().getNodes()[0];
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is_null_argument_to_indices[is_null_argument].push_back(or_operands.size() - 1);
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}
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}
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}
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}
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/// OR operands that are changed to and needs to be re-resolved
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std::unordered_set<size_t> arguments_to_reresolve;
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for (size_t equals_function_idx : equals_functions_indices)
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{
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auto * equals_function = or_operands[equals_function_idx]->as<FunctionNode>();
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/// For a <=> b we are looking for expressions containing both `a IS NULL` and `b IS NULL` combined with AND
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const auto & argument_nodes = equals_function->getArguments().getNodes();
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const auto & lhs_is_null_parents = is_null_argument_to_indices[argument_nodes[0]];
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const auto & rhs_is_null_parents = is_null_argument_to_indices[argument_nodes[1]];
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std::unordered_set<size_t> operands_to_optimize;
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std::set_intersection(lhs_is_null_parents.begin(), lhs_is_null_parents.end(),
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rhs_is_null_parents.begin(), rhs_is_null_parents.end(),
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std::inserter(operands_to_optimize, operands_to_optimize.begin()));
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/// If we have `a = b OR (a IS NULL AND b IS NULL)` we can optimize it to `a <=> b`
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if (!operands_to_optimize.empty() && equals_function->getFunctionName() == "equals")
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arguments_to_reresolve.insert(equals_function_idx);
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for (size_t to_optimize_idx : operands_to_optimize)
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{
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/// We are looking for operand `a IS NULL AND b IS NULL AND ...`
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auto * operand_to_optimize = or_operands[to_optimize_idx]->as<FunctionNode>();
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/// Remove `a IS NULL` and `b IS NULL` arguments from AND
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QueryTreeNodes new_arguments;
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for (const auto & and_argument : operand_to_optimize->getArguments().getNodes())
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{
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bool to_eliminate = false;
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const auto * and_argument_function = and_argument->as<FunctionNode>();
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if (and_argument_function && and_argument_function->getFunctionName() == "isNull")
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{
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const auto & is_null_argument = and_argument_function->getArguments().getNodes()[0];
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to_eliminate = (is_null_argument->isEqual(*argument_nodes[0]) || is_null_argument->isEqual(*argument_nodes[1]));
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}
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if (to_eliminate)
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arguments_to_reresolve.insert(to_optimize_idx);
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else
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new_arguments.emplace_back(and_argument);
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}
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/// If less than two arguments left, we will remove or replace the whole AND below
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operand_to_optimize->getArguments().getNodes() = std::move(new_arguments);
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}
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}
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if (arguments_to_reresolve.empty())
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/// Nothing have been changed
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return;
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auto and_function_resolver = FunctionFactory::instance().get("and", getContext());
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auto strict_equals_function_resolver = FunctionFactory::instance().get("isNotDistinctFrom", getContext());
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QueryTreeNodes new_or_operands;
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for (size_t i = 0; i < or_operands.size(); ++i)
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{
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if (arguments_to_reresolve.contains(i))
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{
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auto * function = or_operands[i]->as<FunctionNode>();
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if (function->getFunctionName() == "equals")
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{
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/// Because we removed checks for IS NULL, we should replace `a = b` with `a <=> b`
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function->resolveAsFunction(strict_equals_function_resolver);
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new_or_operands.emplace_back(std::move(or_operands[i]));
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}
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else if (function->getFunctionName() == "and")
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{
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const auto & and_arguments = function->getArguments().getNodes();
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if (and_arguments.size() > 1)
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{
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function->resolveAsFunction(and_function_resolver);
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new_or_operands.emplace_back(std::move(or_operands[i]));
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}
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else if (and_arguments.size() == 1)
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{
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/// Replace AND with a single argument with the argument itself
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new_or_operands.emplace_back(and_arguments[0]);
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}
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}
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else
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throw Exception(ErrorCodes::LOGICAL_ERROR, "Unexpected function name: '{}'", function->getFunctionName());
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}
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else
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{
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new_or_operands.emplace_back(std::move(or_operands[i]));
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}
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}
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if (new_or_operands.size() == 1)
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{
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node = std::move(new_or_operands[0]);
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return;
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}
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/// Rebuild OR function
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auto or_function_resolver = FunctionFactory::instance().get("or", getContext());
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function_node.getArguments().getNodes() = std::move(new_or_operands);
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function_node.resolveAsFunction(or_function_resolver);
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}
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bool is_inside_on_section = false;
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std::deque<const JoinNode *> join_stack;
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};
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void LogicalExpressionOptimizerPass::run(QueryTreeNodePtr query_tree_node, ContextPtr context)
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