Shulou(Shulou.com)06/01 Report--

1. The introduction of delete process is divided into two stages: search and update. Lock the clustered index record during the search phase, refer to the previous article. In the update phase, the clustered index records will be tagged with delete, and then the secondary index records will be search. The secondary index records will be implicitly locked, that is, unlocked. Finally, the secondary index records will be tagged with delete.

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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. Lock principle flow chart

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