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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008-2009 Sun Microsystems
*
* 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_OPTIMIZER_TABLE_READ_PLAN_H
#define DRIZZLED_OPTIMIZER_TABLE_READ_PLAN_H
namespace drizzled
{
class SEL_TREE;
struct st_ror_scan_info;
namespace optimizer
{
class Parameter;
class SEL_ARG;
/*
Table rows retrieval plan. Range optimizer creates QuickSelectInterface-derived
objects from table read plans.
*/
class TableReadPlan
{
public:
/*
Plan read cost, with or without cost of full row retrieval, depending
on plan creation parameters.
*/
double read_cost;
ha_rows records; /* estimate of #rows to be examined */
/*
If true, the scan returns rows in rowid order. This is used only for
scans that can be both ROR and non-ROR.
*/
bool is_ror;
/*
Create quick select for this plan.
SYNOPSIS
make_quick()
param Parameter from test_quick_select
retrieve_full_rows If true, created quick select will do full record
retrieval.
parent_alloc Memory pool to use, if any.
NOTES
retrieve_full_rows is ignored by some implementations.
RETURN
created quick select
NULL on any error.
*/
virtual QuickSelectInterface *make_quick(Parameter *param,
bool retrieve_full_rows,
memory::Root *parent_alloc= NULL) = 0;
/* Table read plans are allocated on memory::Root and are never deleted */
static void *operator new(size_t size, memory::Root *mem_root)
{
return (void*) alloc_root(mem_root, (uint32_t) size);
}
static void operator delete(void *, size_t)
{ }
static void operator delete(void *, memory::Root *)
{ /* Never called */ }
virtual ~TableReadPlan() {} /* Remove gcc warning */
};
/*
Plan for a QuickRangeSelect scan.
RangeReadPlan::make_quick ignores retrieve_full_rows parameter because
QuickRangeSelect doesn't distinguish between 'index only' scans and full
record retrieval scans.
*/
class RangeReadPlan : public TableReadPlan
{
public:
RangeReadPlan(SEL_ARG *key_arg, uint32_t idx_arg, uint32_t mrr_flags_arg)
:
key(key_arg),
key_idx(idx_arg),
mrr_flags(mrr_flags_arg),
mrr_buf_size(0)
{}
virtual ~RangeReadPlan() {} /* Remove gcc warning */
QuickSelectInterface *make_quick(Parameter *param, bool, memory::Root *parent_alloc);
void setMRRBufferSize(uint32_t in_mrr_buf_size)
{
mrr_buf_size= in_mrr_buf_size;
}
uint32_t getKeyIndex() const
{
return key_idx;
}
uint32_t getMRRBufferSize() const
{
return mrr_buf_size;
}
private:
/** set of intervals to be used in "range" method retrieval */
SEL_ARG *key;
/** key number in Parameter::key */
uint32_t key_idx;
uint32_t mrr_flags;
uint32_t mrr_buf_size;
};
/* Plan for QuickRorIntersectSelect scan. */
class RorIntersectReadPlan : public TableReadPlan
{
public:
RorIntersectReadPlan()
:
ror_range_scans(),
cpk_scan(NULL),
is_covering(false),
index_scan_costs(0.0)
{}
virtual ~RorIntersectReadPlan() {} /* Remove gcc warning */
QuickSelectInterface *make_quick(Parameter *param,
bool retrieve_full_rows,
memory::Root *parent_alloc);
void setRowRetrievalNecessary(bool in_is_covering)
{
is_covering= in_is_covering;
}
void setCostOfIndexScans(double in_index_scan_costs)
{
index_scan_costs= in_index_scan_costs;
}
/**
* @return true if row retrival phase is necessary.
*/
bool isRowRetrievalNecessary() const
{
return ! is_covering;
}
/**
* @return the sum of the cost of each index scan
*/
double getCostOfIndexScans() const
{
return index_scan_costs;
}
/** Vector of pointers to ROR range scans used in this intersection */
std::vector<struct st_ror_scan_info *> ror_range_scans;
struct st_ror_scan_info *cpk_scan; /* Clustered PK scan, if there is one */
private:
/** true if no row retrieval phase is necessary */
bool is_covering;
/* SUM(cost(index_scan)) */
double index_scan_costs;
};
/*
Plan for QuickRorUnionSelect scan.
QuickRorUnionSelect always retrieves full rows, so retrieve_full_rows
is ignored by make_quick.
*/
class RorUnionReadPlan : public TableReadPlan
{
public:
RorUnionReadPlan() {} /* Remove gcc warning */
virtual ~RorUnionReadPlan() {} /* Remove gcc warning */
QuickSelectInterface *make_quick(Parameter *param,
bool retrieve_full_rows,
memory::Root *parent_alloc);
/** vector of plans for merged scans */
std::vector<TableReadPlan *> merged_scans;
};
/*
Plan for QuickIndexMergeSelect scan.
QuickRorIntersectSelect always retrieves full rows, so retrieve_full_rows
is ignored by make_quick.
*/
class IndexMergeReadPlan : public TableReadPlan
{
public:
IndexMergeReadPlan() {} /* Remove gcc warning */
virtual ~IndexMergeReadPlan() {} /* Remove gcc warning */
QuickSelectInterface *make_quick(Parameter *param,
bool retrieve_full_rows,
memory::Root *parent_alloc);
RangeReadPlan **range_scans; /* array of ptrs to plans of merged scans */
RangeReadPlan **range_scans_end; /* end of the array */
};
/*
Plan for a QuickGroupMinMaxSelect scan.
*/
class GroupMinMaxReadPlan : public TableReadPlan
{
public:
GroupMinMaxReadPlan(bool have_min_arg,
bool have_max_arg,
KEY_PART_INFO *min_max_arg_part_arg,
uint32_t group_prefix_len_arg,
uint32_t used_key_parts_arg,
uint32_t group_key_parts_arg,
KEY *index_info_arg,
uint32_t index_arg,
uint32_t key_infix_len_arg,
unsigned char *key_infix_arg,
SEL_TREE *tree_arg,
SEL_ARG *index_tree_arg,
uint32_t param_idx_arg,
ha_rows quick_prefix_records_arg)
:
quick_prefix_records(quick_prefix_records_arg),
have_min(have_min_arg),
have_max(have_max_arg),
min_max_arg_part(min_max_arg_part_arg),
group_prefix_len(group_prefix_len_arg),
used_key_parts(used_key_parts_arg),
group_key_parts(group_key_parts_arg),
index_info(index_info_arg),
index(index_arg),
key_infix_len(key_infix_len_arg),
range_tree(tree_arg),
index_tree(index_tree_arg),
param_idx(param_idx_arg)
{
if (key_infix_len)
memcpy(this->key_infix, key_infix_arg, key_infix_len);
}
virtual ~GroupMinMaxReadPlan() {} /* Remove gcc warning */
QuickSelectInterface *make_quick(Parameter *param,
bool retrieve_full_rows,
memory::Root *parent_alloc);
/* Number of records selected by the ranges in index_tree. */
ha_rows quick_prefix_records;
private:
bool have_min;
bool have_max;
KEY_PART_INFO *min_max_arg_part;
uint32_t group_prefix_len;
uint32_t used_key_parts;
uint32_t group_key_parts;
KEY *index_info;
uint32_t index;
uint32_t key_infix_len;
unsigned char key_infix[MAX_KEY_LENGTH];
SEL_TREE *range_tree; /* Represents all range predicates in the query. */
SEL_ARG *index_tree; /* The SEL_ARG sub-tree corresponding to index_info. */
uint32_t param_idx; /* Index of used key in param->key. */
};
} /* namespace optimizer */
} /* namespace drizzled */
#endif /* DRIZZLED_OPTIMIZER_TABLE_READ_PLAN_H */
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