MySQL  8.0.27
Source Code Documentation
opt_statistics.h
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1 #ifndef OPT_STATISTICS_INCLUDED
2 #define OPT_STATISTICS_INCLUDED
3 
4 /*
5  Copyright (c) 2014, 2021, Oracle and/or its affiliates.
6 
7  This program is free software; you can redistribute it and/or modify
8  it under the terms of the GNU General Public License, version 2.0,
9  as published by the Free Software Foundation.
10 
11  This program is also distributed with certain software (including
12  but not limited to OpenSSL) that is licensed under separate terms,
13  as designated in a particular file or component or in included license
14  documentation. The authors of MySQL hereby grant you an additional
15  permission to link the program and your derivative works with the
16  separately licensed software that they have included with MySQL.
17 
18  This program is distributed in the hope that it will be useful,
19  but WITHOUT ANY WARRANTY; without even the implied warranty of
20  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21  GNU General Public License, version 2.0, for more details.
22 
23  You should have received a copy of the GNU General Public License
24  along with this program; if not, write to the Free Software
25  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
26 
27 #include <sys/types.h>
28 
29 #include "my_inttypes.h" // IWYU pragma: keep
30 
31 struct TABLE;
32 
33 typedef float rec_per_key_t;
34 class KEY;
35 
36 /**
37  Guesstimate for "records per key" when index statistics is not available.
38 
39  @param table the table
40  @param key the index
41  @param used_keyparts the number of key part that should be included in the
42  estimate
43 
44  @return estimated records per key value
45 */
46 
47 rec_per_key_t guess_rec_per_key(const TABLE *const table, const KEY *const key,
48  uint used_keyparts);
49 
50 #endif /* OPT_STATISTICS_INCLUDED */
Definition: key.h:112
TABLE * table
Definition: key.h:202
float rec_per_key_t
Data type for records per key estimates that are stored in the KEY::rec_per_key_float[] array.
Definition: key.h:95
Some integer typedefs for easier portability.
rec_per_key_t guess_rec_per_key(const TABLE *const table, const KEY *const key, uint used_keyparts)
Guesstimate for "records per key" when index statistics is not available.
Definition: opt_statistics.cc:60
float rec_per_key_t
Definition: opt_statistics.h:31
required string key
Definition: replication_asynchronous_connection_failover.proto:59
Definition: table.h:1394
unsigned int uint
Definition: uca-dump.cc:29