Character Set Considerations +------------+------------+--------+ 17 rows in set (0.01 sec) Explanation: The statement requests a list of all the tables in database  db5 , showing just three pieces of information: the name of the table, its type, and its storage engine. The definition for character columns (for example,  TABLES.TABLE_NAME ) is generally  VARCHAR( N ) CHARACTER SET utf8  where  N  is at least 64. MySQL uses the default collation for this character set ( utf8_general_ci ) for all searches, sorts, comparisons, and other string operations on such columns. Because some MySQL objects are represented as files, searches in  INFORMATION_SCHEMA  string columns can be affected by file system case sensitivity. For more information, see Section 10.8.7, “Using Collation in INFORMATION_SCHEMA Searches” . The  SELECT ... FROM INFORMATION_SCHEMA  statement is intended as a more consistent way to provide access to the information provided by the various  SHOW  statements that MySQL supports ( SHOW DATABASES ,  SHOW TABLES , and so forth). Using  SELECT  has these advantages, compared to  SHOW : Because  SHOW  is familiar and widely used, the  SHOW  statements remain as an alternative. In fact, along with the implementation of  INFORMATION_SCHEMA , there are enhancements to  SHOW  as described in Section 26.8, “Extensions to SHOW Statements” . For most  INFORMATION_SCHEMA  tables, each MySQL user has the right to access them, but can see only the rows in the tables that correspond to objects for which the user has the proper access privileges. In some cases (for example, the  ROUTINE_DEFINITION  column in the  INFORMATION_SCHEMA ROUTINES table), users who have insufficient privileges see  NULL . Some tables have different privilege requirements; for these, the requirements are mentioned in the applicable table descriptions. For example,  InnoDB  tables (tables with names that begin with  INNODB_ ) require the  PROCESS  privilege. The same privileges apply to selecting information from  INFORMATION_SCHEMA  and viewing the same information through  SHOW  statements. In either case, you must have some privilege on an object to see information about it. INFORMATION_SCHEMA  queries that search for information from more than one database might take a long time and impact performance. To check the efficiency of a query, you can use  EXPLAIN . For information about using  EXPLAIN  output to tune  INFORMATION_SCHEMA  queries, see Section 8.2.3, “Optimizing INFORMATION_SCHEMA Queries” . 4770 Performance Considerations INFORMATION_SCHEMA and Privileges INFORMATION_SCHEMA as Alternative to SHOW Statements Character Set Considerations •It conforms to Codd’s rules, because all access is done on tables. •You can use the familiar syntax of the  SELECT  statement, and only need to learn some table and column names. •The implementor need not worry about adding keywords. •You can filter, sort, concatenate, and transform the results from  INFORMATION_SCHEMA  queries into whatever format your application needs, such as a data structure or a text representation to parse. •This technique is more interoperable with other database systems. For example, Oracle Database users are familiar with querying tables in the Oracle data dictionary.