1MYSQLCHECK(1) MySQL Database System MYSQLCHECK(1)
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6 mysqlcheck - a table maintenance program
7
9 mysqlcheck [options] [db_name [tbl_name ...]]
10
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 (see Section 13.3.6, “LOCK TABLES and
18 UNLOCK TABLES Statements”, for more information about READ and WRITE
19 locks). Table maintenance operations can be time-consuming,
20 particularly for large tables. If you use the --databases or
21 --all-databases option to process all tables in one or more databases,
22 an invocation of mysqlcheck might take a long time. (This is also true
23 for the MySQL upgrade procedure if it determines that table checking is
24 needed because it processes tables the same way.)
25 mysqlcheck must be used when the mysqld server is running, which means
27 that you do not have to stop the server to perform table maintenance.
28 mysqlcheck uses the SQL statements CHECK TABLE, REPAIR TABLE, ANALYZE
30 TABLE, and OPTIMIZE TABLE in a convenient way for the user. It
31 determines which statements to use for the operation you want to
32 perform, and then sends the statements to the server to be executed.
33 For details about which storage engines each statement works with, see
34 the descriptions for those statements in Section 13.7.3, “Table
35 Maintenance Statements”.
36 All storage engines do not necessarily support all four maintenance
38 operations. In such cases, an error message is displayed. For example,
39 if test.t is an MEMORY table, an attempt to check it produces this
40 result:
41 shell> mysqlcheck test t
43 test.t
44 note : The storage engine for the table doesn't support check
45 If mysqlcheck is unable to repair a table, see Section 2.11.13,
47 “Rebuilding or Repairing Tables or Indexes” for manual table repair
48 strategies. This is the case, for example, for InnoDB tables, which can
49 be checked with CHECK TABLE, but not repaired with REPAIR TABLE.
50 Caution
52 It is best to make a backup of a table before performing a table
53 repair operation; under some circumstances the operation might
54 cause data loss. Possible causes include but are not limited to
55 file system errors.
56 There are three general ways to invoke mysqlcheck:
58 mysqlcheck [options] db_name [tbl_name ...]
60 mysqlcheck [options] --databases db_name ...
61 mysqlcheck [options] --all-databases
62 If you do not name any tables following db_name or if you use the
64 --databases or --all-databases option, entire databases are checked.
65 mysqlcheck has a special feature compared to other client programs. The
67 default behavior of checking tables (--check) can be changed by
68 renaming the binary. If you want to have a tool that repairs tables by
69 default, you should just make a copy of mysqlcheck named mysqlrepair,
70 or make a symbolic link to mysqlcheck named mysqlrepair. If you invoke
71 mysqlrepair, it repairs tables.
72 The names shown in the following table can be used to change mysqlcheck
74 default behavior.
75 ┌──────────────┬───────────────────────┐
77 │Command │ Meaning │
78 ├──────────────┼───────────────────────┤
79 │mysqlrepair │ The default option is │
80 │ │ --repair │
81 ├──────────────┼───────────────────────┤
82 │mysqlanalyze │ The default option is │
83 │ │ --analyze │
84 ├──────────────┼───────────────────────┤
85 │mysqloptimize │ The default option is │
86 │ │ --optimize │
87 └──────────────┴───────────────────────┘
88 mysqlcheck supports the following options, which can be specified on
90 the command line or in the [mysqlcheck] and [client] groups of an
91 option file. For information about option files used by MySQL programs,
92 see Section 4.2.2.2, “Using Option Files”.
93 • --help, -? Display a help message and exit.
95 • --all-databases, -A Check all tables in all databases. This is the
97 same as using the --databases option and naming all the databases
98 on the command line, except that the INFORMATION_SCHEMA and
99 performance_schema databases are not checked. They can be checked
100 by explicitly naming them with the --databases option.
101 • --all-in-1, -1 Instead of issuing a statement for each table,
103 execute a single statement for each database that names all the
104 tables from that database to be processed.
105 • --analyze, -a Analyze the tables.
107 • --auto-repair If a checked table is corrupted, automatically fix
109 it. Any necessary repairs are done after all tables have been
110 checked.
111 • --bind-address=ip_address On a computer having multiple network
113 interfaces, use this option to select which interface to use for
114 connecting to the MySQL server.
115 • --character-sets-dir=dir_name The directory where character sets
117 are installed. See Section 10.15, “Character Set Configuration”.
118 • --check, -c Check the tables for errors. This is the default
120 operation.
121 • --check-only-changed, -C Check only tables that have changed since
123 the last check or that have not been closed properly.
124 • --check-upgrade, -g Invoke CHECK TABLE with the FOR UPGRADE option
126 to check tables for incompatibilities with the current version of
127 the server.
128 • --compress Compress all information sent between the client and the
130 server if possible. See Section 4.2.8, “Connection Compression
131 Control”.
132 As of MySQL 8.0.18, this option is deprecated. Expect it to be
134 removed in a future version of MySQL. See the section called
135 “Configuring Legacy Connection Compression”.
136 • --compression-algorithms=value The permitted compression algorithms
138 for connections to the server. The available algorithms are the
139 same as for the protocol_compression_algorithms system variable.
140 The default value is uncompressed.
141 For more information, see Section 4.2.8, “Connection Compression
143 Control”.
144 This option was added in MySQL 8.0.18.
146 • --databases, -B Process all tables in the named databases.
148 Normally, mysqlcheck treats the first name argument on the command
149 line as a database name and any following names as table names.
150 With this option, it treats all name arguments as database names.
151 • --debug[=debug_options], -# [debug_options] Write a debugging log.
153 A typical debug_options string is d:t:o,file_name. The default is
154 d:t:o.
155 This option is available only if MySQL was built using WITH_DEBUG.
157 MySQL release binaries provided by Oracle are not built using this
158 option.
159 • --debug-check Print some debugging information when the program
161 exits.
162 This option is available only if MySQL was built using WITH_DEBUG.
164 MySQL release binaries provided by Oracle are not built using this
165 option.
166 • --debug-info Print debugging information and memory and CPU usage
168 statistics when the program exits.
169 This option is available only if MySQL was built using WITH_DEBUG.
171 MySQL release binaries provided by Oracle are not built using this
172 option.
173 • --default-character-set=charset_name Use charset_name as the
175 default character set. See Section 10.15, “Character Set
176 Configuration”.
177 • --defaults-extra-file=file_name Read this option file after the
179 global option file but (on Unix) before the user option file. If
180 the file does not exist or is otherwise inaccessible, an error
181 occurs. If file_name is not an absolute path name, it is
182 interpreted relative to the current directory.
183 For additional information about this and other option-file
185 options, see Section 4.2.2.3, “Command-Line Options that Affect
186 Option-File Handling”.
187 • --defaults-file=file_name Use only the given option file. If the
189 file does not exist or is otherwise inaccessible, an error occurs.
190 If file_name is not an absolute path name, it is interpreted
191 relative to the current directory.
192 Exception: Even with --defaults-file, client programs read
194 .mylogin.cnf.
195 For additional information about this and other option-file
197 options, see Section 4.2.2.3, “Command-Line Options that Affect
198 Option-File Handling”.
199 • --defaults-group-suffix=str Read not only the usual option groups,
201 but also groups with the usual names and a suffix of str. For
202 example, mysqlcheck normally reads the [client] and [mysqlcheck]
203 groups. If this option is given as --defaults-group-suffix=_other,
204 mysqlcheck also reads the [client_other] and [mysqlcheck_other]
205 groups.
206 For additional information about this and other option-file
208 options, see Section 4.2.2.3, “Command-Line Options that Affect
209 Option-File Handling”.
210 • --extended, -e If you are using this option to check tables, it
212 ensures that they are 100% consistent but takes a long time.
213 If you are using this option to repair tables, it runs an extended
215 repair that may not only take a long time to execute, but may
216 produce a lot of garbage rows also!
217 • --default-auth=plugin A hint about which client-side authentication
219 plugin to use. See Section 6.2.17, “Pluggable Authentication”.
220 • --enable-cleartext-plugin Enable the mysql_clear_password cleartext
222 authentication plugin. (See Section 6.4.1.4, “Client-Side Cleartext
223 Pluggable Authentication”.)
224 • --fast, -F Check only tables that have not been closed properly.
226 • --force, -f Continue even if an SQL error occurs.
228 • --get-server-public-key Request from the server the public key
230 required for RSA key pair-based password exchange. This option
231 applies to clients that authenticate with the caching_sha2_password
232 authentication plugin. For that plugin, the server does not send
233 the public key unless requested. This option is ignored for
234 accounts that do not authenticate with that plugin. It is also
235 ignored if RSA-based password exchange is not used, as is the case
236 when the client connects to the server using a secure connection.
237 If --server-public-key-path=file_name is given and specifies a
239 valid public key file, it takes precedence over
240 --get-server-public-key.
241 For information about the caching_sha2_password plugin, see
243 Section 6.4.1.2, “Caching SHA-2 Pluggable Authentication”.
244 • --host=host_name, -h host_name Connect to the MySQL server on the
246 given host.
247 • --login-path=name Read options from the named login path in the
249 .mylogin.cnf login path file. A “login path” is an option group
250 containing options that specify which MySQL server to connect to
251 and which account to authenticate as. To create or modify a login
252 path file, use the mysql_config_editor utility. See
253 mysql_config_editor(1).
254 For additional information about this and other option-file
256 options, see Section 4.2.2.3, “Command-Line Options that Affect
257 Option-File Handling”.
258 • --medium-check, -m Do a check that is faster than an --extended
260 operation. This finds only 99.99% of all errors, which should be
261 good enough in most cases.
262 • --no-defaults Do not read any option files. If program startup
264 fails due to reading unknown options from an option file,
265 --no-defaults can be used to prevent them from being read.
266 The exception is that the .mylogin.cnf file is read in all cases,
268 if it exists. This permits passwords to be specified in a safer way
269 than on the command line even when --no-defaults is used. To create
270 .mylogin.cnf, use the mysql_config_editor utility. See
271 mysql_config_editor(1).
272 For additional information about this and other option-file
274 options, see Section 4.2.2.3, “Command-Line Options that Affect
275 Option-File Handling”.
276 • --optimize, -o Optimize the tables.
278 • --password[=password], -p[password] The password of the MySQL
280 account used for connecting to the server. The password value is
281 optional. If not given, mysqlcheck prompts for one. If given, there
282 must be no space between --password= or -p and the password
283 following it. If no password option is specified, the default is to
284 send no password.
285 Specifying a password on the command line should be considered
287 insecure. To avoid giving the password on the command line, use an
288 option file. See Section 6.1.2.1, “End-User Guidelines for Password
289 Security”.
290 To explicitly specify that there is no password and that mysqlcheck
292 should not prompt for one, use the --skip-password option.
293 • --pipe, -W On Windows, connect to the server using a named pipe.
295 This option applies only if the server was started with the
296 named_pipe system variable enabled to support named-pipe
297 connections. In addition, the user making the connection must be a
298 member of the Windows group specified by the
299 named_pipe_full_access_group system variable.
300 • --plugin-dir=dir_name The directory in which to look for plugins.
302 Specify this option if the --default-auth option is used to specify
303 an authentication plugin but mysqlcheck does not find it. See
304 Section 6.2.17, “Pluggable Authentication”.
305 • --port=port_num, -P port_num For TCP/IP connections, the port
307 number to use.
308 • --print-defaults Print the program name and all options that it
310 gets from option files.
311 For additional information about this and other option-file
313 options, see Section 4.2.2.3, “Command-Line Options that Affect
314 Option-File Handling”.
315 • --protocol={TCP|SOCKET|PIPE|MEMORY} The transport protocol to use
317 for connecting to the server. It is useful when the other
318 connection parameters normally result in use of a protocol other
319 than the one you want. For details on the permissible values, see
320 Section 4.2.7, “Connection Transport Protocols”.
321 • --quick, -q If you are using this option to check tables, it
323 prevents the check from scanning the rows to check for incorrect
324 links. This is the fastest check method.
325 If you are using this option to repair tables, it tries to repair
327 only the index tree. This is the fastest repair method.
328 • --repair, -r Perform a repair that can fix almost anything except
330 unique keys that are not unique.
331 • --server-public-key-path=file_name The path name to a file in PEM
333 format containing a client-side copy of the public key required by
334 the server for RSA key pair-based password exchange. This option
335 applies to clients that authenticate with the sha256_password or
336 caching_sha2_password authentication plugin. This option is ignored
337 for accounts that do not authenticate with one of those plugins. It
338 is also ignored if RSA-based password exchange is not used, as is
339 the case when the client connects to the server using a secure
340 connection.
341 If --server-public-key-path=file_name is given and specifies a
343 valid public key file, it takes precedence over
344 --get-server-public-key.
345 For sha256_password, this option applies only if MySQL was built
347 using OpenSSL.
348 For information about the sha256_password and caching_sha2_password
350 plugins, see Section 6.4.1.3, “SHA-256 Pluggable Authentication”,
351 and Section 6.4.1.2, “Caching SHA-2 Pluggable Authentication”.
352 • --shared-memory-base-name=name On Windows, the shared-memory name
354 to use for connections made using shared memory to a local server.
355 The default value is MYSQL. The shared-memory name is
356 case-sensitive.
357 This option applies only if the server was started with the
359 shared_memory system variable enabled to support shared-memory
360 connections.
361 • --silent, -s Silent mode. Print only error messages.
363 • --skip-database=db_name Do not include the named database
365 (case-sensitive) in the operations performed by mysqlcheck.
366 • --socket=path, -S path For connections to localhost, the Unix
368 socket file to use, or, on Windows, the name of the named pipe to
369 use.
370 On Windows, this option applies only if the server was started with
372 the named_pipe system variable enabled to support named-pipe
373 connections. In addition, the user making the connection must be a
374 member of the Windows group specified by the
375 named_pipe_full_access_group system variable.
376 • --ssl* Options that begin with --ssl specify whether to connect to
378 the server using encryption and indicate where to find SSL keys and
379 certificates. See the section called “Command Options for Encrypted
380 Connections”.
381 • --ssl-fips-mode={OFF|ON|STRICT} Controls whether to enable FIPS
383 mode on the client side. The --ssl-fips-mode option differs from
384 other --ssl-xxx options in that it is not used to establish
385 encrypted connections, but rather to affect which cryptographic
386 operations to permit. See Section 6.8, “FIPS Support”.
387 These --ssl-fips-mode values are permitted:
389 • OFF: Disable FIPS mode.
391 • ON: Enable FIPS mode.
393 • STRICT: Enable “strict” FIPS mode.
395 Note
398 If the OpenSSL FIPS Object Module is not available, the only
399 permitted value for --ssl-fips-mode is OFF. In this case,
400 setting --ssl-fips-mode to ON or STRICT causes the client to
401 produce a warning at startup and to operate in non-FIPS mode.
402 • --tables Override the --databases or -B option. All name arguments
404 following the option are regarded as table names.
405 • --tls-ciphersuites=ciphersuite_list The permissible ciphersuites
407 for encrypted connections that use TLSv1.3. The value is a list of
408 one or more colon-separated ciphersuite names. The ciphersuites
409 that can be named for this option depend on the SSL library used to
410 compile MySQL. For details, see Section 6.3.2, “Encrypted
411 Connection TLS Protocols and Ciphers”.
412 This option was added in MySQL 8.0.16.
414 • --tls-version=protocol_list The permissible TLS protocols for
416 encrypted connections. The value is a list of one or more
417 comma-separated protocol names. The protocols that can be named for
418 this option depend on the SSL library used to compile MySQL. For
419 details, see Section 6.3.2, “Encrypted Connection TLS Protocols and
420 Ciphers”.
421 • --use-frm For repair operations on MyISAM tables, get the table
423 structure from the data dictionary so that the table can be
424 repaired even if the .MYI header is corrupted.
425 • --user=user_name, -u user_name The user name of the MySQL account
427 to use for connecting to the server.
428 • --verbose, -v Verbose mode. Print information about the various
430 stages of program operation.
431 • --version, -V Display version information and exit.
433 • --write-binlog This option is enabled by default, so that ANALYZE
435 TABLE, OPTIMIZE TABLE, and REPAIR TABLE statements generated by
436 mysqlcheck are written to the binary log. Use --skip-write-binlog
437 to cause NO_WRITE_TO_BINLOG to be added to the statements so that
438 they are not logged. Use the --skip-write-binlog when these
439 statements should not be sent to replicas or run when using the
440 binary logs for recovery from backup.
441 • --zstd-compression-level=level The compression level to use for
443 connections to the server that use the zstd compression algorithm.
444 The permitted levels are from 1 to 22, with larger values
445 indicating increasing levels of compression. The default zstd
446 compression level is 3. The compression level setting has no effect
447 on connections that do not use zstd compression.
448 For more information, see Section 4.2.8, “Connection Compression
450 Control”.
451 This option was added in MySQL 8.0.18.
453
455 Copyright © 1997, 2021, Oracle and/or its affiliates.
456 This documentation is free software; you can redistribute it and/or
458 modify it only under the terms of the GNU General Public License as
459 published by the Free Software Foundation; version 2 of the License.
460 This documentation is distributed in the hope that it will be useful,
462 but WITHOUT ANY WARRANTY; without even the implied warranty of
463 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
464 General Public License for more details.
465 You should have received a copy of the GNU General Public License along
467 with the program; if not, write to the Free Software Foundation, Inc.,
468 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see
469 http://www.gnu.org/licenses/.
470
473 For more information, please refer to the MySQL Reference Manual, which
474 may already be installed locally and which is also available online at
475 http://dev.mysql.com/doc/.
476
478 Oracle Corporation (http://dev.mysql.com/).
479MySQL 8.0 03/07/2021 MYSQLCHECK(1)