Skip to main content

MY.L6.DEFAULT_STORAGE_ENGINE_NOT_INNODB — a table with no transactions and no foreign keys

  • Category: safety
  • Level: 6
  • Confidence: deterministic
  • Downtime class: none
  • Stability: stable
  • Suites: audit
  • Applies to: MySQL 8.4
  • Not transferable to MariaDB: this page describes MySQL 8.4 behavior. MariaDB answers the same driver and does not share these semantics, so SQLens refuses it outright rather than reasoning about it — see drivers/unsupported.

A table created without an explicit ENGINE takes the server default.

Under MyISAM that table has no transactions, no foreign keys and no crash recovery — and none of those absences raise anything:

  • a migration wrapped in a transaction simply does not roll back,
  • a foreign key is silently not enforced,
  • an unclean shutdown leaves the table needing repair.

Laravel's schema builder emits ENGINE only when database.connections.mysql.engine is configured, which is not the default. So the server value usually decides.

Flagged​

SET GLOBAL default_storage_engine = MyISAM;

Preferred​

SET GLOBAL default_storage_engine = InnoDB;

The one rule here that says pass out loud​

A server can have default_storage_engine = MyISAM while disabled_storage_engines names MyISAM. The setting then looks wrong and cannot bite: no table can be created under an engine the server refuses to load.

Reporting nothing there would be indistinguishable from a rule that never ran. Reporting a failure would send somebody to change a setting that is already harmless. So this case is reported as a pass with its reason stated — one of the very few places in SQLens where a pass is a finding rather than silence.

Correcting the default is still worth doing. It removes a trap for whoever later shortens that refusal list.

What is read, and what is not​

Only the server's value; the variable is settable per session, and a connection that set its own says nothing about what the next CREATE TABLE from somewhere else will inherit.

The comparison folds case — a my.cnf saying default_storage_engine=innodb produces the same behavior, and flagging it would be a pure spelling false positive. The refusal list is matched per entry, never as a substring.

If disabled_storage_engines could not be read at all, the rule reports undetermined rather than assuming nothing is disabled: "we could not ask" and "nothing is refused" are different sentences.

When this is expected​

A deliberately mixed engine landscape. It is rare, and it belongs on the ignore list with the reason recorded there.

Sources​