InnoDB transaction Lock Line Lock-delete process UPD Phase Lock process

1. Introduction

Delete Process Division search and update two stages. Lock the clustered index record in the search phase, referring to the previous article. The update phase deletes the clustered index record, then search the two-level index record, record the Garin lock on the level two index, without locking, and finally the delete label on the two-level index record.

Mysql_delete::
	//rr_quick->...->row_search_for_mysql while
	(!) ( Error=info.read_record (&info)) &&!thd->killed &&! Thd->is_error ()) {
		...
		...->row_update_for_mysql
		error= table->file->ha_delete_row (table->record[0]);
		...
	}

2. Process schematic diagram