summaryrefslogtreecommitdiff
path: root/sql/sql_olap.cc
blob: 21deef8c664f3c8175d75ca66eee0a7e62fe5eed (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
/* Copyright (C) 2000-2006 MySQL AB

   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */


/*
  OLAP implementation by Sinisa Milivojevic <sinisa@mysql.com>
  Inspired by code submitted by Srilakshmi <lakshmi@gdit.iiit.net>

  The ROLLUP code in this file has to be complitely rewritten as it's
  not good enough to satisfy the goals of MySQL.

  In 4.1 we will replace this with a working, superior implementation
  of ROLLUP.
*/

#ifdef DISABLED_UNTIL_REWRITTEN_IN_4_1

#ifdef USE_PRAGMA_IMPLEMENTATION
#pragma implementation				// gcc: Class implementation
#endif

#include "mysql_priv.h"
#include "sql_select.h"


/****************************************************************************
  Functions that recursively actually creates new SELECT's
  Returns 0 if OK, 1 if error, -1 if error already printed to client
****************************************************************************/


static int make_new_olap_select(LEX *lex, SELECT_LEX *select_lex, List<Item> new_fields)
{
  THD	*thd=current_thd;
  Item *item, *new_item;
  Item_null *constant= new Item_null("ALL");

  SELECT_LEX *new_select = (SELECT_LEX *) thd->memdup((char*) select_lex, sizeof(*select_lex));
  if (!new_select)
    return 1;
  lex->last_selects->next=new_select;
  new_select->linkage=OLAP_TYPE;
  new_select->olap=NON_EXISTING_ONE;
  new_select->group_list.elements=0;
  new_select->group_list.first=(uchar *)0;
  new_select->group_list.next=(uchar **)&new_select->group_list.first;
  List<Item> privlist;
  
  List_iterator<Item> list_it(select_lex->item_list);
  List_iterator<Item> new_it(new_fields);
    
  while ((item=list_it++))
  {
    bool not_found= TRUE;
    if (item->type()==Item::FIELD_ITEM)
    {
      Item_field *iif = (Item_field *)item;
      new_it.rewind();
      while ((new_item=new_it++))
      {
	if (new_item->type()==Item::FIELD_ITEM && 
	    !strcmp(((Item_field*)new_item)->table_name,iif->table_name) &&
	    !strcmp(((Item_field*)new_item)->field_name,iif->field_name))
	{
	  not_found= 0;
	  ((Item_field*)new_item)->db_name=iif->db_name;
	  Item_field *new_one=new Item_field(&select_lex->context,
                                             iif->db_name, iif->table_name, iif->field_name);
	  privlist.push_back(new_one);
	  if (add_to_list(new_select->group_list,new_one,1))
	    return 1;
	  break;
	}
      }
    }
    if (not_found)
    {
      if (item->type() == Item::FIELD_ITEM)
	privlist.push_back(constant);
      else
	privlist.push_back((Item*)thd->memdup((char *)item,item->size_of()));
    }
  }
  new_select->item_list=privlist;

  lex->last_selects = new_select;
  return 0;
}

/****************************************************************************
  Functions that recursively creates combinations of queries for OLAP
  Returns 0 if OK, 1 if error, -1 if error already printed to client
****************************************************************************/

static int  olap_combos(List<Item> old_fields, List<Item> new_fields, Item *item, LEX *lex, 
			      SELECT_LEX *select_lex, int position, int selection, int num_fields, 
			      int num_new_fields)
{
  int sl_return = 0;
  if (position == num_new_fields)
  {
    if (item)
      new_fields.push_front(item);
    sl_return = make_new_olap_select(lex, select_lex, new_fields);
  }
  else
  {
    if (item)
      new_fields.push_front(item);
    while ((num_fields - num_new_fields >= selection - position) && !sl_return)
    {
      item = old_fields.pop();
      sl_return = olap_combos(old_fields, new_fields, item, lex, select_lex, position+1, ++selection, num_fields, num_new_fields);
    }
  }
  return sl_return;
}


/****************************************************************************
  Top level function for converting OLAP clauses to multiple selects
  This is also a place where clauses treatment depends on OLAP type 
  Returns 0 if OK, 1 if error, -1 if error already printed to client
****************************************************************************/

int handle_olaps(LEX *lex, SELECT_LEX *select_lex)
{
  List<Item> item_list_copy, new_item_list;
  item_list_copy.empty();
  new_item_list.empty();
  int count=select_lex->group_list.elements;
  int sl_return=0;


  lex->last_selects=select_lex;

  for (ORDER *order= select_lex->group_list.first ; order ; order=order->next)
    item_list_copy.push_back(*(order->item));

  List<Item>	all_fields(select_lex->item_list);


  if (setup_tables(lex->thd, &select_lex->context, &select_lex->top_join_list,
                   select_lex->table_list.first
                   &select_lex->leaf_tables, FALSE) ||
      setup_fields(lex->thd, 0, select_lex->item_list, MARK_COLUMNS_READ,
                   &all_fields,1) ||
      setup_fields(lex->thd, 0, item_list_copy, MARK_COLUMNS_READ,
                   &all_fields, 1))
    return -1;

  if (select_lex->olap == CUBE_TYPE)
  {
    for ( int i=count-1; i>=0 && !sl_return; i--)
      sl_return=olap_combos(item_list_copy, new_item_list, (Item *)0, lex, select_lex, 0, 0, count, i);
  }
  else if (select_lex->olap == ROLLUP_TYPE)
  {
    for ( int i=count-1; i>=0 && !sl_return; i--)
    {
      Item *item;
      item_list_copy.pop();
      List_iterator<Item> it(item_list_copy);
      new_item_list.empty();
      while ((item = it++))
	new_item_list.push_front(item);
      sl_return=make_new_olap_select(lex, select_lex, new_item_list);
    }
  }
  else
    sl_return=1; // impossible
  return sl_return;
}

#endif /* DISABLED_UNTIL_REWRITTEN_IN_4_1 */