set global innodb_commit_concurrency=0; select @@innodb_commit_concurrency; @@innodb_commit_concurrency 0 set global innodb_commit_concurrency=1; ERROR 42000: Variable 'innodb_commit_concurrency' can't be set to the value of '1' select @@innodb_commit_concurrency; @@innodb_commit_concurrency 0 set global innodb_commit_concurrency=42; ERROR 42000: Variable 'innodb_commit_concurrency' can't be set to the value of '42' select @@innodb_commit_concurrency; @@innodb_commit_concurrency 0 set global innodb_commit_concurrency=0; select @@innodb_commit_concurrency; @@innodb_commit_concurrency 0 set global innodb_commit_concurrency=DEFAULT; select @@innodb_commit_concurrency; @@innodb_commit_concurrency 0