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#pragma once
#include <Analyzer/IQueryTreePass.h>
namespace DB
{
/** Convert `if` chain into single `multiIf`.
* Replace if(cond_1, then_1_value, if(cond_2, ...)) chains into multiIf(cond_1, then_1_value, cond_2, ...).
*
* Example: SELECT if(cond_1, then_1_value, if(cond_2, then_2_value, else_value));
* Result: SELECT multiIf(cond_1, then_1_value, cond_2, then_2_value, else_value);
*/
class IfChainToMultiIfPass final : public IQueryTreePass
{
public:
String getName() override { return "IfChainToMultiIf"; }
String getDescription() override { return "Optimize if chain to multiIf"; }
void run(QueryTreeNodePtr query_tree_node, ContextPtr context) override;
};
}
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