1MYSQLCHECK(1) MariaDB Database System MYSQLCHECK(1)
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6 mysqlcheck - a table maintenance program
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9 mysqlcheck [options] [db_name [tbl_name ...]]
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12 The mysqlcheck client performs table maintenance: It checks, repairs,
13 optimizes, or analyzes tables.
14 Each table is locked and therefore unavailable to other sessions while
16 it is being processed, although for check operations, the table is
17 locked with a READ lock only. Table maintenance operations can be
18 time-consuming, particularly for large tables. If you use the
19 --databases or --all-databases option to process all tables in one or
20 more databases, an invocation of mysqlcheck might take a long time.
21 (This is also true for mysql_upgrade because that program invokes
22 mysqlcheck to check all tables and repair them if necessary.)
23 mysqlcheck is similar in function to myisamchk, but works differently.
25 The main operational difference is that mysqlcheck must be used when
26 the mysqld server is running, whereas myisamchk should be used when it
27 is not. The benefit of using mysqlcheck is that you do not have to stop
28 the server to perform table maintenance.
29 mysqlcheck uses the SQL statements CHECK TABLE, REPAIR TABLE, ANALYZE
31 TABLE, and OPTIMIZE TABLE in a convenient way for the user. It
32 determines which statements to use for the operation you want to
33 perform, and then sends the statements to the server to be executed.
34 The MyISAM storage engine supports all four maintenance operations, so
36 mysqlcheck can be used to perform any of them on MyISAM tables. Other
37 storage engines do not necessarily support all operations. In such
38 cases, an error message is displayed. For example, if test.t is a
39 MEMORY table, an attempt to check it produces this result:
40 shell> mysqlcheck test t
42 test.t
43 note : The storage engine for the table doesn´t support check
44 If mysqlcheck is unable to repair a table, see the MariaDB Knowledge
46 Base for manual table repair strategies. This will be the case, for
47 example, for InnoDB tables, which can be checked with CHECK TABLE, but
48 not repaired with REPAIR TABLE.
49 The use of mysqlcheck with partitioned tables is not supported.
51 Caution
53 It is best to make a backup of a table before performing a table
54 repair operation; under some circumstances the operation might
55 cause data loss. Possible causes include but are not limited to
56 file system errors.
57 There are three general ways to invoke mysqlcheck:
59 shell> mysqlcheck [options] db_name [tbl_name ...]
61 shell> mysqlcheck [options] --databases db_name ...
62 shell> mysqlcheck [options] --all-databases
63 If you do not name any tables following db_name or if you use the
65 --databases or --all-databases option, entire databases are checked.
66 mysqlcheck has a special feature compared to other client programs. The
68 default behavior of checking tables (--check) can be changed by
69 renaming the binary. If you want to have a tool that repairs tables by
70 default, you should just make a copy of mysqlcheck named mysqlrepair,
71 or make a symbolic link to mysqlcheck named mysqlrepair. If you invoke
72 mysqlrepair, it repairs tables.
73 The following names can be used to change mysqlcheck default behavior.
75 ┌──────────────┬───────────────────────┐
77 │mysqlrepair │ The default option is │
78 │ │ --repair │
79 ├──────────────┼───────────────────────┤
80 │mysqlanalyze │ The default option is │
81 │ │ --analyze │
82 ├──────────────┼───────────────────────┤
83 │mysqloptimize │ The default option is │
84 │ │ --optimize │
85 └──────────────┴───────────────────────┘
86 mysqlcheck supports the following options, which can be specified on
88 the command line or in the [mysqlcheck] and [client] option file
89 groups. The -c, -r, -a and -o options are exclusive to each other.
90 · --help, -?
92 Display a help message and exit.
94 · --all-databases, -A
96 Check all tables in all databases. This is the same as using the
98 --databases option and naming all the databases on the command
99 line.
100 · --all-in-1, -1
102 Instead of issuing a statement for each table, execute a single
104 statement for each database that names all the tables from that
105 database to be processed.
106 · --analyze, -a
108 Analyze the tables.
110 · --auto-repair
112 If a checked table is corrupted, automatically fix it. Any
114 necessary repairs are done after all tables have been checked.
115 · --character-sets-dir=path
117 The directory where character sets are installed.
119 · --check, -c
121 Check the tables for errors. This is the default operation.
123 · --check-only-changed, -C
125 Check only tables that have changed since the last check or that
127 have not been closed properly.
128 · --check-upgrade, -g
130 Invoke CHECK TABLE with the FOR UPGRADE option to check tables for
132 incompatibilities with the current version of the server. This
133 option automatically enables the --fix-db-names and
134 --fix-table-names options.
135 · --compress
137 Compress all information sent between the client and the server if
139 both support compression.
140 · --databases, -B
142 Process all tables in the named databases. Normally, mysqlcheck
144 treats the first name argument on the command line as a database
145 name and following names as table names. With this option, it
146 treats all name arguments as database names.
147 · --debug[=debug_options], -# [debug_options]
149 Write a debugging log. A typical debug_options string is
151 ´d:t:o,file_name´. The default is ´d:t:o´.
152 · --debug-check
154 Print some debugging information when the program exits.
156 · --debug-info
158 Print debugging information and memory and CPU usage statistics
160 when the program exits.
161 · --default-auth=name
163 Default authentication client-side plugin to use.
165 · --default-character-set=charset_name
167 Use charset_name as the default character set.
169 · --defaults-extra-file=filename
171 Set filename as the file to read default options from after the
173 global defaults files has been read. Must be given as first
174 option.
175 · --defaults-file=filename
177 Set filename as the file to read default options from, override
179 global defaults files. Must be given as first option.
180 · --extended, -e
182 If you are using this option to check tables, it ensures that they
184 are 100% consistent but takes a long time.
185 If you are using this option to repair tables, it will force using
187 the old, slow, repair with keycache method, instead of the much
188 faster repair by sorting.
189 · --fast, -F
191 Check only tables that have not been closed properly.
193 · --fix-db-names
195 Convert database names to the format used since MySQL 5.1. Only
197 database names that contain special characters are affected.
198 · --fix-table-names
200 Convert table names (including views) to the format used since
202 MySQL 5.1. Only table names that contain special characters are
203 affected.
204 · --flush,
206 Flush each table after check. This is useful if you don't want to
208 have the checked tables take up space in the caches after the
209 check.
210 · --force, -f
212 Continue even if an SQL error occurs.
214 · --host=host_name, -h host_name
216 Connect to the MariaDB server on the given host.
218 · --medium-check, -m
220 Do a check that is faster than an --extended operation. This finds
222 only 99.99% of all errors, which should be good enough in most
223 cases.
224 · --no-defaults
226 Do not read default options from any option file. This must be
228 given as the first argument.
229 · --optimize, -o
231 Optimize the tables.
233 · --password[=password], -p[password]
235 The password to use when connecting to the server. If you use the
237 short option form (-p), you cannot have a space between the option
238 and the password. If you omit the password value following the
239 --password or -p option on the command line, mysqlcheck prompts for
240 one.
241 Specifying a password on the command line should be considered
243 insecure. You can use an option file to avoid giving the password
244 on the command line.
245 · --persistent, -Z
247 Used with ANALYZE TABLE to append the option PERSISENT FOR ALL.
249 · --pipe, -W
251 On Windows, connect to the server via a named pipe. This option
253 applies only if the server supports named-pipe connections.
254 · --plugin-dir=name
256 Directory for client-side plugins.
258 · --port=port_num, -P port_num
260 The TCP/IP port number to use for the connection.
262 · --print-defaults
264 Print the program argument list and exit. This must be given as
266 the first argument.
267 · --process-tables
269 Perform the requested operation on tables. Defaults to on; use
271 --skip-process-tables to disable.
272 · --process-views=val
274 Perform the requested operation (only CHECK VIEW or REPAIR VIEW).
276 Possible values are NO, YES (correct the checksum, if necessary,
277 add the mariadb-version field), UPGRADE_FROM_MYSQL (same as YES and
278 toggle the algorithm MERGE<->TEMPTABLE.
279 · --protocol={TCP|SOCKET|PIPE|MEMORY}
281 The connection protocol to use for connecting to the server. It is
283 useful when the other connection parameters normally would cause a
284 protocol to be used other than the one you want.
285 · --quick, -q
287 If you are using this option to check tables, it prevents the check
289 from scanning the rows to check for incorrect links. This is the
290 fastest check method.
291 If you are using this option to repair tables, it tries to repair
293 only the index tree. This is the fastest repair method.
294 · --repair, -r
296 Perform a repair that can fix almost anything except unique keys
298 that are not unique.
299 · --silent, -s
301 Silent mode. Print only error messages.
303 · --skip-database=db_name -s
305 Don't process the database (case-sensitive) specified as argument.
307 · --socket=path, -S path
309 For connections to localhost, the Unix socket file to use, or, on
311 Windows, the name of the named pipe to use.
312 · --ssl
314 Enable SSL for connection (automatically enabled with other flags).
316 Disable with --skip-ssl.
317 · --ssl-ca=name
319 CA file in PEM format (check OpenSSL docs, implies --ssl).
321 · --ssl-capath=name
323 CA directory (check OpenSSL docs, implies --ssl).
325 · --ssl-cert=name
327 X509 cert in PEM format (check OpenSSL docs, implies --ssl).
329 · --ssl-cipher=name
331 SSL cipher to use (check OpenSSL docs, implies --ssl).
333 · --ssl-key=name
335 X509 key in PEM format (check OpenSSL docs, implies --ssl).
337 · --ssl-crl=name
339 Certificate revocation list (check OpenSSL docs, implies --ssl).
341 · --ssl-crlpath=name
343 Certificate revocation list path (check OpenSSL docs, implies
345 --ssl).
346 · --ssl-verify-server-cert
348 Verify server's "Common Name" in its cert against hostname used
350 when connecting. This option is disabled by default.
351 · --tables
353 Override the --databases or -B option. All name arguments following
355 the option are regarded as table names.
356 · --use-frm
358 For repair operations on MyISAM tables, get the table structure
360 from the .frm file so that the table can be repaired even if the
361 .MYI header is corrupted.
362 · --user=user_name, -u user_name
364 The MariaDB user name to use when connecting to the server.
366 · --verbose, -v
368 Verbose mode. Print information about the various stages of program
370 operation. Using one --verbose option will give you more
371 information about what mysqlcheck is doing.
372 Using two --verbose options will also give you connection
374 information.
375 Using it 3 times will print out all CHECK, RENAME and ALTER TABLE
377 during the check phase.
378 · --version, -V
380 Display version information and exit.
382 · --write-binlog
384 This option is enabled by default, so that ANALYZE TABLE, OPTIMIZE
386 TABLE, and REPAIR TABLE statements generated by mysqlcheck are
387 written to the binary log. Use --skip-write-binlog to cause
388 NO_WRITE_TO_BINLOG to be added to the statements so that they are
389 not logged. Use the --skip-write-binlog when these statements
390 should not be sent to replication slaves or run when using the
391 binary logs for recovery from backup.
392
394 Copyright 2007-2008 MySQL AB, 2008-2010 Sun Microsystems, Inc.,
395 2010-2015 MariaDB Foundation
396 This documentation is free software; you can redistribute it and/or
398 modify it only under the terms of the GNU General Public License as
399 published by the Free Software Foundation; version 2 of the License.
400 This documentation is distributed in the hope that it will be useful,
402 but WITHOUT ANY WARRANTY; without even the implied warranty of
403 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
404 General Public License for more details.
405 You should have received a copy of the GNU General Public License along
407 with the program; if not, write to the Free Software Foundation, Inc.,
408 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA or see
409 http://www.gnu.org/licenses/.
410
413 For more information, please refer to the MariaDB Knowledge Base,
414 available online at https://mariadb.com/kb/
415
417 MariaDB Foundation (http://www.mariadb.org/).
418MariaDB 10.4 28 March 2019 MYSQLCHECK(1)