Bulk Migrations

[jri]

The migration facility currently doesn't support bulk updates (thousands of operations) as the framework creates an outer transaction which exceeds capacity.
(There is deliberately a *single* transaction wrapping a plugin clean install which includes all the plugin's initial migrations. See note below.)

Possible solution:
The concept of "Bulk Migrations" which are responsible for transaction handling themself.

Note: a Bulk Migration might not be allowed while a plugin clean install as the POST_INSTALL_PLUGIN event must fire exactly once.