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#pragma once
#include <Analyzer/IQueryTreePass.h>
namespace DB
{
/** If ORDER BY has argument x followed by f(x) transforms it to ORDER BY x.
* Optimize ORDER BY x, y, f(x), g(x, y), f(h(x)), t(f(x), g(x)) into ORDER BY x, y
* in case if f(), g(), h(), t() are deterministic (in scope of query).
* Don't optimize ORDER BY f(x), g(x), x even if f(x) is bijection for x or g(x).
*/
class OptimizeRedundantFunctionsInOrderByPass final : public IQueryTreePass
{
public:
String getName() override { return "OptimizeRedundantFunctionsInOrderBy"; }
String getDescription() override { return "If ORDER BY has argument x followed by f(x) transforms it to ORDER BY x."; }
void run(QueryTreeNodePtr query_tree_node, ContextPtr context) override;
};
}
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