MySQL 8.4 Release Notes
25.5.10 ndb_drop_index — 从 NDB 表中删除索引
ndb_drop_index drops the specified index from an NDB table. It is recommended that you use this utility only as an example for writing NDB API applications—see the Warning later in this section for details.
ndb_drop_index -c connection_string table_name index -d db_nameThe statement shown above drops the index named index from the table in the database.
Options that can be used with ndb_drop_index are shown in the following table. Additional descriptions follow the table.
-
Command-Line Format --character-sets-dir=pathDirectory containing character sets.
-
Command-Line Format --connect-retries=#Type Integer Default Value 12Minimum Value 0Maximum Value 12Number of times to retry connection before giving up.
-
Command-Line Format --connect-retry-delay=#Type Integer Default Value 5Minimum Value 0Maximum Value 5Number of seconds to wait between attempts to contact management server.
-
Command-Line Format --connect-string=connection_stringType String Default Value [none]Same as
--ndb-connectstring. -
Command-Line Format --core-fileWrite core file on error; used in debugging.
-
--database,-dCommand-Line Format --database=nameType String Default Value TEST_DBName of the database in which the table resides.
-
Command-Line Format --defaults-extra-file=pathType String Default Value [none]Read given file after global files are read.
-
Command-Line Format --defaults-file=pathType String Default Value [none]Read default options from given file only.
-
Command-Line Format --defaults-group-suffix=stringType String Default Value [none]Also read groups with concat(group, suffix).
-
Command-Line Format --helpDisplay help text and exit.
-
Command-Line Format --login-path=pathType String Default Value [none]Read given path from login file.
-
Command-Line Format --no-login-pathsSkips reading options from the login path file.
-
Command-Line Format --ndb-connectstring=connection_stringType String Default Value [none]Set connection string for connecting to ndb_mgmd. Syntax:
[nodeid=. Overrides entries inid;][host=]hostname[:port]NDB_CONNECTSTRINGandmy.cnf. -
Command-Line Format --ndb-mgm-tls=levelType Enumeration Default Value relaxedValid Values relaxedstrictSets the level of TLS support required to connect to the management server; one of
relaxedorstrict.relaxed(the default) means that a TLS connection is attempted, but success is not required;strictmeans that TLS is required to connect. -
Command-Line Format --ndb-mgmd-host=connection_stringType String Default Value [none]Same as
--ndb-connectstring. -
Command-Line Format --ndb-nodeid=#Type Integer Default Value [none]Set node ID for this node, overriding any ID set by
--ndb-connectstring. -
--ndb-optimized-node-selectionCommand-Line Format --ndb-optimized-node-selectionEnable optimizations for selection of nodes for transactions. Enabled by default; use
--skip-ndb-optimized-node-selectionto disable. -
Command-Line Format --ndb-tls-search-path=listType Path name Default Value (Unix) $HOME/ndb-tlsDefault Value (Windows) $HOMEDIR/ndb-tlsSpecify a list of directories to search for a CA file. On Unix platforms, the directory names are separated by colons (
:); on Windows systems, the semicolon character (;) is used as the separator. A directory reference may be relative or absolute; it may contain one or more environment variables, each denoted by a prefixed dollar sign ($), and expanded prior to use.Searching begins with the leftmost named directory and proceeds from left to right until a file is found. An empty string denotes an empty search path, which causes all searches to fail. A string consisting of a single dot (
.) indicates that the search path limited to the current working directory.If no search path is supplied, the compiled-in default value is used. This value depends on the platform used: On Windows, this is
\ndb-tls; on other platforms (including Linux), it is$HOME/ndb-tls. This can be overridden by compiling NDB Cluster using-DWITH_NDB_TLS_SEARCH_PATH. -
Command-Line Format --no-defaultsDo not read default options from any option file other than login file.
-
Command-Line Format --print-defaultsPrint program argument list and exit.
-
Command-Line Format --usageDisplay help text and exit; same as
--help. -
Command-Line Format --versionDisplay version information and exit.
Warning
Operations performed on Cluster table indexes using the NDB API are not visible to MySQL and make the table unusable by a MySQL server. If you use this program to drop an index, then try to access the table from an SQL node, an error results, as shown here:
$> ./ndb_drop_index -c localhost dogs ix -d ctest1
Dropping index dogs/idx...OK
$> ./mysql -u jon -p ctest1
Enter password: *******
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 7 to server version: 5.7.44-ndb-7.5.32
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> SHOW TABLES;
+------------------+
| Tables_in_ctest1 |
+------------------+
| a |
| bt1 |
| bt2 |
| dogs |
| employees |
| fish |
+------------------+
6 rows in set (0.00 sec)
mysql> SELECT * FROM dogs;
ERROR 1296 (HY000): Got error 4243 'Index not found' from NDBCLUSTERIn such a case, your only option for making the table available to MySQL again is to drop the table and re-create it. You can use either the SQL statementDROP TABLE or the ndb_drop_table utility (see Section 25.5.11, “ndb_drop_table — Drop an NDB Table”) to drop the table.