Note: for questions where you can select multiple answers, it will tell you how many to choose.
- Lots of InnoDB and transactional stuff
- Understand everything about locking
- Setting default storage engine:
storage_engine = MyISAM;
- READ UNCOMMITTED isolation level
This isolation level allows dirty reads. One transaction may see uncommitted changes made by some other transaction. You should pretty much never do this anyway.
- READ COMMITTED isolation level
A somewhat Oracle-like isolation level with respect to consistent (nonlocking) reads: Each consistent read, even within the same transaction, sets and reads its own fresh snapshot.
- INFORMATION_SCHEMA.SCHEMATA
A schema is a database, so the SCHEMATA table provides information about databases.
INFORMATION_SCHEMA Name SHOW Name Remarks
CATALOG_NAME NULL
SCHEMA_NAME Database
DEFAULT_CHARACTER_SET_NAME
DEFAULT_COLLATION_NAME
SQL_PATH NULL
-
To repair an InnoDB table, you cannot use
REPAIR table
. You must dump the table and reimport it. -
Importing multiple binary logs into MySQL:
mysqlbinlog binlog.001 binlog.002 binlog.003 | mysql
OR
mysqlbinlog binlog.001 | mysql
mysqlbinlog binlog.002 | mysql
mysqlbinlog binlog.003 | mysql
-
InnoDB tablespace files are machine independent.
-
To make a binary copy of the InnoDB tablespace, you need to copy:
- All tablespace files, including the files for the shared tablespace and .ibd files if you have con- figured InnoDB to use per-table tablespaces
- All InnoDB log files
- The .frm file for each of your InnoDB tables
- The InnoDB tablespace and log configuration information stored in your MySQL option file (that is, the settings for innodb_data_home_dir, innodb_data_file_path, and perhaps other InnoDB options)
- Configuration files are read in the following order:
- /etc/my.cnf
- /etc/mysql/my.cnf
- SYSCONFDIR/my.cnf
- $MYSQL_HOME/my.cnf
- defaults-extra-file The file specified with --defaults-extra-file=path, if any
- ~/.my.cnf
-
SELECT ... INTO OUTFILE 'filename'
cannot overwrite (or append to) existing files, and the file will be world-readable. -
You cannot make a binary copy of InnoDB tables while the server is running. Unlike the options avail- able when using MyISAM tables (lock the tables, flush them to disk, and then copy them), you must tell the server to stop before making a copy of InnoDB files. This is necessary to ensure that InnoDB has completed any pending transactions before the copy is made.
-
When using InnoDB,
SELECT ... FOR UPDATE
is used to select a set of rows that you later intend to update. -
If you install MySQL with a different service name on Windows, the server ignores the
[mysqld]
option group and instead reads options from the group that has the same name as the service. For example, if you name the serviceMySQL5
, it will read configuration options in the group[MySQL5]