InnoDB Page Compression emp_no INT NOT NULL, birth_date DATE NOT NULL, first_name VARCHAR(14) NOT NULL, last_name VARCHAR(16) NOT NULL, gender ENUM (’M’,’F’) NOT NULL, hire_date DATE NOT NULL, PRIMARY KEY (emp_no) ) COMPRESSION="zlib"; # Insert data (not shown) # Query page compression metadata in INFORMATION_SCHEMA.INNODB_TABLESPACES mysql>  SELECT SPACE, NAME, FS_BLOCK_SIZE, FILE_SIZE, ALLOCATED_SIZE FROM INFORMATION_SCHEMA.INNODB_TABLESPACES WHERE NAME=’employees/employees’\G *************************** 1. row *************************** SPACE: 45 NAME: employees/employees FS_BLOCK_SIZE: 4096 FILE_SIZE: 23068672 ALLOCATED_SIZE: 19415040 Page compression metadata for the employees table shows that the apparent file size is 23068672 bytes while the actual file size (with page compression) is 19415040 bytes. The file system block size is 4096 bytes, which is the block size used for hole punching. To identify tables for which page compression is enabled, you can query the INFORMATION_SCHEMA.TABLES CREATE_OPTIONS  column for tables defined with the  COMPRESSION attribute: SHOW CREATE TABLE  also shows the  COMPRESSION  attribute, if used. Page Compression Limitations and Usage Notes Identifying Tables Using Page Compression mysql>  SELECT TABLE_NAME, TABLE_SCHEMA, CREATE_OPTIONS FROM INFORMATION_SCHEMA.TABLES  WHERE CREATE_OPTIONS LIKE ’%COMPRESSION=%’; +------------+--------------+--------------------+ | TABLE_NAME | TABLE_SCHEMA | CREATE_OPTIONS | +------------+--------------+--------------------+ | employees | test | COMPRESSION="zlib" | +------------+--------------+--------------------+ •Loading a page-compressed tablespace on a server that does not support the compression algorithm that was used causes an I/O error. 3164 •During recovery, updated pages are written out in an uncompressed form. •Pages that belong to compressed tables ( ROW_FORMAT=COMPRESSED ) are left as-is. •R-tree pages, which are used for spatial indexes, are not compressed. •Page compression is not supported for redo log pages. •Page compression is not supported for undo log tablespaces. •Page compression is not supported for tables that reside in shared tablespaces, which include the system tablespace, temporary tablespaces, and general tablespaces. •Page compression is disabled if the file system block size (or compression unit size on Windows) * 2 > innodb_page_size .