inno sdi

Extract SDI (Serialized Dictionary Information) metadata from MySQL 8.0+ tablespaces.

Synopsis

inno sdi -f <file> [--pretty] [--page-size <size>] [--keyring <path>]

Locates SDI pages in a tablespace by scanning for page type 17853 (FIL_PAGE_SDI), then reassembles multi-page SDI records by following the page chain. The zlib-compressed payload is decompressed and printed as JSON.

Each tablespace in MySQL 8.0+ embeds its own table, column, and index definitions as SDI records, eliminating the need for the .frm files used in MySQL 5.x. This command extracts that embedded metadata for inspection, backup verification, or schema reconstruction.

SDI records contain:

Table SDI (type 1): Full table definition including column names, types, charset, default values, and index definitions.
Tablespace SDI (type 2): Tablespace properties.

Use --pretty for indented JSON output. Without it, the raw JSON string from the SDI record is printed as-is.

MariaDB tablespaces do not use SDI. Running this command against a MariaDB tablespace will produce an error message explaining that MariaDB stores metadata differently.

Flags

Flag	Short	Required	Default	Description
`--file <path>`	`-f`	Yes	--	Path to the InnoDB data file (.ibd).
`--pretty`	`-p`	No	Off	Pretty-print the extracted JSON with indentation.
`--page-size <size>`	--	No	Auto-detect	Override page size.
`--keyring <path>`	--	No	--	Path to MySQL keyring file for decrypting encrypted tablespaces.

Examples

Extract SDI metadata

inno sdi -f /var/lib/mysql/sakila/actor.ibd

Pretty-print the JSON output

inno sdi -f actor.ibd --pretty

Pipe to jq for column extraction

inno sdi -f actor.ibd --pretty | jq '.dd_object.columns[].name'

Extract SDI from an encrypted tablespace

inno sdi -f encrypted_table.ibd --keyring /path/to/keyring --pretty

Output

Found 1 SDI page(s): [3]

=== SDI Record: type=1 (Table), id=373
Compressed: 482 bytes, Uncompressed: 2048 bytes
{
  "mysqld_version_id": 80400,
  "dd_version": 80300,
  "sdi_version": 80019,
  "dd_object_type": "Table",
  "dd_object": {
    "name": "actor",
    "columns": [
      { "name": "actor_id", "type": 4, ... },
      { "name": "first_name", "type": 16, ... },
      { "name": "last_name", "type": 16, ... },
      { "name": "last_update", "type": 18, ... }
    ],
    "indexes": [
      { "name": "PRIMARY", "type": 1, ... },
      { "name": "idx_actor_last_name", "type": 2, ... }
    ],
    ...
  }
}

Total SDI records: 1

If the tablespace has no SDI pages (e.g., a pre-MySQL 8.0 file):

No SDI pages found in actor.ibd.
SDI is only available in MySQL 8.0+ tablespaces.

IDB Utils Documentation