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26 lines
678 B
C++
26 lines
678 B
C++
#pragma once
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#include <Interpreters/InDepthNodeVisitor.h>
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#include <Storages/StorageInMemoryMetadata.h>
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namespace DB
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{
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class ASTFunction;
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/// Rewrites functions to subcolumns, if possible, to reduce amount of read data.
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/// E.g. 'length(arr)' -> 'arr.size0', 'col IS NULL' -> 'col.null'
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class RewriteFunctionToSubcolumnData
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{
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public:
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using TypeToVisit = ASTFunction;
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void visit(ASTFunction & function, ASTPtr & ast) const;
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StorageMetadataPtr metadata_snapshot;
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};
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using RewriteFunctionToSubcolumnMatcher = OneTypeMatcher<RewriteFunctionToSubcolumnData>;
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using RewriteFunctionToSubcolumnVisitor = InDepthNodeVisitor<RewriteFunctionToSubcolumnMatcher, true>;
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}
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