Marko Mäkelä added a comment - 2019-05-20 11:29 First of all, the table flags are not the same as tablespace flags ( FSP_SPACE_FLAGS ). There are some MariaDB specific changes to both. Also, the dict_table_t::flags do not fully correspond to SYS_TABLES.TYPE , and INNODB_SYS_TABLES.FLAG is actually not reporting SYS_TABLES.TYPE , but dict_table_t::flags that corresponds to the data dictionary record. Bit 0 (the least significant) bit is set if ROW_FORMAT is not REDUNDANT . Bits 1‥4 are 0, except for ROW_FORMAT=COMPRESSED , where they will determine the KEY_BLOCK_SIZE (the compressed page size). Bit 5 is set for ROW_FORMAT=DYNAMIC or ROW_FORMAT=COMPRESSED . Bit 6 is set if the DATA DIRECTORY attribute was present when the table was originally created. Bit 7 is set if the page_compressed attribute is present. Bits 8‥11 determine the page_compression_level . Bits 12‥13 are normally 00, but 11 for "no-rollback tables" (MariaDB 10.3 CREATE SEQUENCE ). In MariaDB 10.1, these bits could be 01 or 10 for ATOMIC_WRITES=ON or ATOMIC_WRITES=OFF. Please check the validity of these claims with some examples.

Valerii Kravchuk added a comment - 2019-05-26 12:41 May I ask where Bit 0 (the least significant) comes from, exactly, on disk? It does not seem to be set in the .ibd file for the table with row_format=Compact (see also INNODB_SYS_TABLESPACES), so where exactly something is stored (on disk)? Also, what about this KB page, https://mariadb.com/kb/en/library/information-schema-innodb_sys_tablespaces-table/ , that still says wrong thing: "FLAG 1 if a DATA DIRECTORY option has been specified in CREATE TABLE, otherwise 0." The above is surely incorrect: MariaDB [test]> select * from information_schema.innodb_sys_tablespaces where name like 'test/ti%'; +-------+----------+------+----------------------+-----------+---------------+------------+---------------+-----------+----------------+ | SPACE | NAME | FLAG | ROW_FORMAT | PAGE_SIZE | ZIP_PAGE_SIZE | SPACE_TYPE | FS_BLOCK_SIZE | FILE_SIZE | ALLOCATED_SIZE | +-------+----------+------+----------------------+-----------+---------------+------------+---------------+-----------+----------------+ | 55 | test/ti1 | 0 | Compact or Redundant | 16384 | 16384 | Single | 4096 | 98304 | 98304 | | 56 | test/ti2 | 0 | Compact or Redundant | 16384 | 16384 | Single | 4096 | 98304 | 98304 | | 57 | test/ti3 | 33 | Dynamic | 16384 | 16384 | Single | 4096 | 98304 | 98304 | | 58 | test/ti4 | 41 | Compressed | 16384 | 8192 | Single | 4096 | 65536 | 65536 | | 59 | test/ti5 | 33 | Dynamic | 16384 | 16384 | Single | 4096 | 98304 | 98304 | +-------+----------+------+----------------------+-----------+---------------+------------+---------------+-----------+----------------+ 5 rows in set (0,001 sec)   MariaDB [test]> show create table test.ti5\G *************************** 1. row *************************** Table: ti5 Create Table: CREATE TABLE `ti5` ( `id` int(11) NOT NULL, `c1` int(11) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 1 row in set (0,001 sec)