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29 lines
582 B
C++
29 lines
582 B
C++
#pragma once
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#include <Interpreters/InDepthNodeVisitor.h>
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namespace DB
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{
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class ASTSelectQuery;
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/// AST transformer. It replaces cross joins with equivalented inner join if possible.
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class CrossToInnerJoinMatcher
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{
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public:
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struct Data
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{
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bool done = false;
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};
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static bool needChildVisit(ASTPtr &, const ASTPtr &) { return true; }
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static void visit(ASTPtr & ast, Data & data);
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private:
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static void visit(ASTSelectQuery & select, ASTPtr & ast, Data & data);
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};
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using CrossToInnerJoinVisitor = InDepthNodeVisitor<CrossToInnerJoinMatcher, true>;
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}
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