From 553ef1a78ba7ba6961c3c99887d405694a04e91b Mon Sep 17 00:00:00 2001 From: Daniel Black Date: Fri, 5 Mar 2021 17:25:15 +1100 Subject: MDEV-13115: Implement SELECT SKIP LOCKED Adds an implementation for SELECT ... FOR UPDATE SKIP LOCKED / SELECT ... LOCK IN SHARED MODE SKIP LOCKED This is implemented only InnoDB at the moment, not in RockDB yet. This adds a new hander flag HA_CAN_SKIP_LOCKED than will be used when the storage engine advertises the flag. When a storage engine indicates this flag it will get TL_WRITE_SKIP_LOCKED and TL_READ_SKIP_LOCKED transaction types. The Lex structure has been updated to store both the FOR UPDATE/LOCK IN SHARE as well as the SKIP LOCKED so the SHOW CREATE VIEW implementation is simplier. "SELECT FOR UPDATE ... SKIP LOCKED" combined with CREATE TABLE AS or INSERT.. SELECT on the result set is not safe for STATEMENT based replication. MIXED replication will replicate this as row based events." Thanks to guidance from Facebook commit https://github.com/facebook/mysql-5.6/commit/193896c466d43fd905a62a60f1d73fd9c551a6e4 This helped verify basic test case, and components that need implementing (even though every part was implemented differently). Thanks Marko for guidance on simplier InnoDB implementation. Reviewers: Marko, Monty --- sql/table.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'sql/table.h') diff --git a/sql/table.h b/sql/table.h index 5a8ee2c1709..f0499ee63fc 100644 --- a/sql/table.h +++ b/sql/table.h @@ -2456,7 +2456,8 @@ struct TABLE_LIST bool updating; /* for replicate-do/ignore table */ bool force_index; /* prefer index over table scan */ bool ignore_leaves; /* preload only non-leaf nodes */ - bool crashed; /* Table was found crashed */ + bool crashed; /* Table was found crashed */ + bool skip_locked; /* Skip locked in view defination */ table_map dep_tables; /* tables the table depends on */ table_map on_expr_dep_tables; /* tables on expression depends on */ struct st_nested_join *nested_join; /* if the element is a nested join */ -- cgit v1.2.1