InnoDB INFORMATION_SCHEMA Schema Object Tables HAS_DEFAULT  and  DEFAULT_VALUE  columns only apply to columns added instantly using  ALTER TABLE ... ADD COLUMN  with  ALGORITHM=INSTANT . INNODB_INDEXES  returns data for two indexes. The first index is  GEN_CLUST_INDEX , which is a clustered index created by  InnoDB  if the table does not have a user-defined clustered index. The second index ( i1 ) is the user-defined secondary index. The  INDEX_ID  is an identifier for the index that is unique across all databases in an instance. The TABLE_ID  identifies the table that the index is associated with. The index  TYPE  value indicates the type of index (1 = Clustered Index, 0 = Secondary index). The  N_FILEDS  value is the number of fields that comprise the index.  PAGE_NO  is the root page number of the index B-tree, and  SPACE  is the ID of the tablespace where the index resides. A nonzero value indicates that the index does not reside in the system tablespace.  MERGE_THRESHOLD  defines a percentage threshold value for the amount of data in an index page. If the amount of data in an index page falls below the this value (the default is 50%) when a row is deleted or when a row is shortened by an update operation,  InnoDB  attempts to merge the index page with a neighboring index page. INNODB_FIELDS  provides the  NAME  of the indexed field and its ordinal position within the index. If the index (i1) had been defined on multiple fields,  INNODB_FIELDS  would provide metadata for each of the indexed fields. 3310 mysql>  SELECT * FROM INFORMATION_SCHEMA.INNODB_TABLESPACES WHERE SPACE = 57 \G *************************** 1. row *************************** SPACE: 57 NAME: test/t1 FLAG: 16417 ROW_FORMAT: Dynamic mysql>  SELECT * FROM INFORMATION_SCHEMA.INNODB_FIELDS where INDEX_ID = 112 \G *************************** 1. row *************************** INDEX_ID: 112 NAME: col1 POS: 0 mysql>  SELECT * FROM INFORMATION_SCHEMA.INNODB_INDEXES WHERE TABLE_ID = 71 \G *************************** 1. row *************************** INDEX_ID: 111 NAME: GEN_CLUST_INDEX TABLE_ID: 71 TYPE: 1 N_FIELDS: 0 PAGE_NO: 3 SPACE: 57 MERGE_THRESHOLD: 50 *************************** 2. row *************************** INDEX_ID: 112 NAME: i1 TABLE_ID: 71 TYPE: 0 N_FIELDS: 1 PAGE_NO: 4 SPACE: 57 MERGE_THRESHOLD: 50 4. Using the  TABLE_ID  information from  INNODB_TABLES  once again, query  INNODB_INDEXES  for information about the indexes associated with table  t1 . 5. Using the  INDEX_ID  information from  INNODB_INDEXES , query  INNODB_FIELDS  for information about the fields of index  i1 . 6. Using the  SPACE  information from  INNODB_TABLES , query  INNODB_TABLESPACES  table for information about the table’s tablespace.