1 /*
2 Copyright (c) 2014, 2015 SkySQL Ab & MariaDB Foundation
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; version 2 of the License.
7
8 This program is distributed in the hope that it will be useful,
9 but WITHOUT ANY WARRANTY; without even the implied warranty of
10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 GNU General Public License for more details.
12
13 You should have received a copy of the GNU General Public License
14 along with this program; if not, write to the Free Software
15 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
16
17 /*
18 This file implements the group_by_handler code. This interface
19 can be used by storage handlers that can intercept summary or GROUP
20 BY queries from MariaDB and itself return the result to the user or
21 upper level.
22 */
23
24 #include "mariadb.h"
25 #include "sql_priv.h"
26 #include "sql_select.h"
27
28 /*
29 Same return values as do_select();
30
31 @retval
32 0 if ok
33 @retval
34 1 if error is sent
35 @retval
36 -1 if error should be sent
37 */
38
execute(JOIN * join)39 int Pushdown_query::execute(JOIN *join)
40 {
41 int err;
42 ha_rows max_limit;
43 bool reset_limit= FALSE;
44 Item **reset_item= 0;
45 THD *thd= handler->thd;
46 TABLE *table= handler->table;
47 DBUG_ENTER("Pushdown_query::execute");
48
49 if ((err= handler->init_scan()))
50 goto error;
51
52 if (store_data_in_temp_table)
53 {
54 max_limit= join->tmp_table_param.end_write_records;
55 reset_limit= TRUE;
56 }
57 else
58 {
59 max_limit= join->unit->lim.get_select_limit();
60 if (join->unit->fake_select_lex)
61 reset_item= &join->unit->fake_select_lex->select_limit;
62 }
63
64 while (!(err= handler->next_row()))
65 {
66 if (unlikely(thd->check_killed()))
67 {
68 handler->end_scan();
69 DBUG_RETURN(-1);
70 }
71
72 /* Check if we can accept the row */
73 if (!having || having->val_bool())
74 {
75 if (store_data_in_temp_table)
76 {
77 if ((err= table->file->ha_write_tmp_row(table->record[0])))
78 {
79 bool is_duplicate;
80 if (likely(!table->file->is_fatal_error(err, HA_CHECK_DUP)))
81 continue; // Distinct elimination
82
83 if (create_internal_tmp_table_from_heap(thd, table,
84 join->tmp_table_param.
85 start_recinfo,
86 &join->tmp_table_param.
87 recinfo,
88 err, 1, &is_duplicate))
89 DBUG_RETURN(1);
90 if (is_duplicate)
91 continue;
92 }
93 }
94 else
95 {
96 if (join->do_send_rows)
97 {
98 int error;
99 /* result < 0 if row was not accepted and should not be counted */
100 if (unlikely((error=
101 join->result->send_data_with_check(*join->fields,
102 join->unit,
103 join->send_records))))
104 {
105 handler->end_scan();
106 DBUG_RETURN(error < 0 ? 0 : -1);
107 }
108 }
109 }
110
111 /* limit handling */
112 if (++join->send_records >= max_limit && join->do_send_rows)
113 {
114 if (!(join->select_options & OPTION_FOUND_ROWS))
115 break; // LIMIT reached
116 join->do_send_rows= 0; // Calculate FOUND_ROWS()
117 if (reset_limit)
118 join->unit->lim.set_unlimited();
119 if (reset_item)
120 *reset_item= 0;
121 }
122 }
123 }
124 if (err != 0 && err != HA_ERR_END_OF_FILE)
125 goto error;
126
127 if ((err= handler->end_scan()))
128 goto error_2;
129 if (!store_data_in_temp_table && join->result->send_eof())
130 DBUG_RETURN(1); // Don't send error to client
131
132 DBUG_RETURN(0);
133
134 error:
135 handler->end_scan();
136 error_2:
137 handler->print_error(err, MYF(0));
138 DBUG_RETURN(-1); // Error not sent to client
139 }
140
141
print_error(int error,myf errflag)142 void group_by_handler::print_error(int error, myf errflag)
143 {
144 my_error(ER_GET_ERRNO, MYF(0), error, hton_name(ht)->str);
145 }
146