Expand description
Engine-level handlerton interface.
Where StorageEngine is per-table, the
handlerton is a per-engine singleton: one instance serves every connection.
An engine opts into engine-level behaviour by implementing Handlerton
and registering it with
register_handlerton. Engines that
need nothing beyond table handling skip registration and keep the
zero-config defaults.
Structs§
- Hton
Capabilities - The set of engine-level features a
Handlertonopts into. - Hton
Flags - A set of
handlertonflags (theHTON_*bits fromsql/handler.h). - Secondary
Engine Optimizer Request - The pair the secondary engine returns from
Handlerton::secondary_engine_check_optimizer_request. - Stat
Print Sink - A handle that lets a
Handlerton::show_statusimplementation push one or more rows of engine status back to MySQL. Bound to the connection andstat_print_fnMySQL handed in, so it does not outlive the callback.
Enums§
- Binlog
Command - The DDL command flavour MySQL is logging through the binary log.
- Binlog
Func - The binlog-related function MySQL is asking the engine to perform.
- Dict
Init Mode - How a data-dictionary backend should initialise its on-disk files.
- Dict
Recovery Mode - Mode for data-dictionary recovery during startup.
- HaClone
Mode - Mode for starting a clone operation.
- HaClone
Type - Clone-transfer type the source engine should perform.
- HaNotification
Type - Whether the notification fires before (pre) or after (post) the event.
- HaPanic
Function - The reason MySQL is invoking the engine-level
paniccallback. - HaStat
Type - Which subset of engine status MySQL wants for
SHOW ENGINE <name> STATUS. - Secondary
Engine Graph Simplification Request - What the secondary engine asks the hypergraph optimizer to do next.
- Select
Executed In - Which engine MySQL executed a
SELECTon, exposed to the post-select notification. - Tablespace
Type - The classification of a data-dictionary tablespace.
- TsCommand
Type - The tablespace DDL command MySQL is asking the engine to validate.
Traits§
- Handlerton
- The engine-level handlerton interface: the capabilities and
handlertonstruct fields that apply to the engine as a whole rather than to a single table. - TxnSession
- The transaction state for one connection.