Online DDL Operations Syntax and Usage Notes •Adding a column •Adding a column cannot be combined in the same statement with other  ALTER TABLE  actions that do not support  ALGORITHM=INSTANT . •A column can only be added as the last column of the table. Adding a column to any other position among other columns is not supported. •Columns cannot be added to tables that use  ROW_FORMAT=COMPRESSED . •Columns cannot be added to tables that include a  FULLTEXT  index. •Columns cannot be added to temporary tables. Temporary tables only support  ALGORITHM=COPY . •Columns cannot be added to tables that reside in the data dictionary tablespace. •Row size limits are not evaluated when adding a column. However, row size limits are checked during DML operations that insert and update rows in the table. INFORMATION_SCHEMA.INNODB_TABLES  and  INFORMATION_SCHEMA.INNODB_COLUMNS  provide metadata for instantly added columns.  INFORMATION_SCHEMA.INNODB_TABLES.INSTANT_COLS shows number of columns in the table prior to adding the first instant column. Multiple columns may be added in the same  ALTER TABLE  statement. For example: The following limitations apply when the  INSTANT  algorithm is used to add a column: ALTER TABLE  tbl_name  ADD COLUMN  column_name column_definition , ALGORITHM=INSTANT; ALTER TABLE t1 ADD COLUMN c2 INT, ADD COLUMN c3 INT, ALGORITHM=INSTANT; 3180 Operation Instant In Place Rebuilds Table Permits Concurrent DML Only Modifies Metadata Extending VARCHAR column size No Yes No Yes Yes Dropping the column default value Yes Yes No Yes Yes Changing the auto-increment value No Yes No Yes No* Making a column  NULL No Yes Yes* Yes No Making a column  NOT NULL No Yes* Yes* Yes No Modifying the definition of an ENUM  or  SET column Yes Yes No Yes Yes