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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008 Sun Microsystems, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef DRIZZLED_NESTED_JOIN_H
#define DRIZZLED_NESTED_JOIN_H
#include <drizzled/sql_list.h>
#include <drizzled/item.h>
#include <drizzled/table_list.h>
#include <bitset>
namespace drizzled
{
struct nested_join_st
{
/* list of elements in the nested join */
List<TableList> join_list;
/* bitmap of tables in the nested join */
table_map used_tables;
/* tables that rejects nulls */
table_map not_null_tables;
/* the first nested table in the plan */
JoinTable *first_nested;
/*
Used to count tables in the nested join in 2 isolated places:
1. In make_outerjoin_info().
2. check_interleaving_with_nj/restore_prev_nj_state (these are called
by the join optimizer.
Before each use the counters are zeroed by reset_nj_counters.
*/
uint32_t counter_;
/* Bit used to identify this nested join*/
std::bitset<64> nj_map;
/*
(Valid only for semi-join nests) Bitmap of tables outside the semi-join
that are used within the semi-join's ON condition.
*/
table_map sj_depends_on;
/* Outer non-trivially correlated tables */
table_map sj_corr_tables;
List<Item> sj_outer_expr_list;
/**
True if this join nest node is completely covered by the query execution
plan. This means two things.
1. All tables on its @c join_list are covered by the plan.
2. All child join nest nodes are fully covered.
*/
bool is_fully_covered() const { return join_list.elements == counter_; }
};
} /* namespace drizzled */
#endif /* DRIZZLED_NESTED_JOIN_H */
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