MySQL
8.0.29
Source Code Documentation
node_map.h
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/* Copyright (c) 2020, Oracle and/or its affiliates.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License, version 2.0,
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as published by the Free Software Foundation.
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This program is also distributed with certain software (including
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but not limited to OpenSSL) that is licensed under separate terms,
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as designated in a particular file or component or in included license
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documentation. The authors of MySQL hereby grant you an additional
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permission to link the program and your derivative works with the
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separately licensed software that they have included with MySQL.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License, version 2.0, for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
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#ifndef SQL_JOIN_OPTIMIZER_NODE_MAP_H
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#define SQL_JOIN_OPTIMIZER_NODE_MAP_H 1
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#include <stdint.h>
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namespace
hypergraph
{
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/**
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Since our graphs can never have more than 61 tables, node sets and edge lists
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are implemented using 64-bit bit sets. This allows for a compact
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representation and very fast set manipulation; the algorithm does a fair
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amount of intersections and unions. If we should need extensions to larger
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graphs later (this will require additional heuristics for reducing the search
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space), we can use dynamic bit sets, although at a performance cost (we'd
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probably templatize off the NodeMap type).
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*/
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using
NodeMap
= uint64_t;
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}
// namespace hypergraph
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#endif
// SQL_JOIN_OPTIMIZER_NODE_MAP_H
hypergraph
Definition:
hypergraph.cc:30
hypergraph::NodeMap
uint64_t NodeMap
Since our graphs can never have more than 61 tables, node sets and edge lists are implemented using 6...
Definition:
node_map.h:39
sql
join_optimizer
node_map.h
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