• Konstantin Osipov's avatar
    Backport of: · c34ac8ee
    Konstantin Osipov authored
    ------------------------------------------------------------
    revno: 2630.13.16
    committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
    branch nick: WL#4284
    timestamp: Sat 2008-07-26 13:38:20 -0300
    message:
    WL#4284: Transactional DDL locking
    
    SQL statements' effect on transactions.
    
    Currently the MySQL server and its storage engines are not
    capable of rolling back operations that define or modify data
    structures (also known as DDL statements) or operations that
    alter any of the system tables (the mysql database). Allowing
    these group of statements to participate in transactions
    is unfeasible at this time (since rollback has no effect
    whatsoever on them) and goes against the design of our metadata
    locking subsystem.
    
    The solution is to issue implicit commits before and after
    those statements execution. This effectively confines each of
    those statements to its own special transaction and ensures
    that metadata locks taken during this special transaction
    are not leaked into posterior statements/transactions.
    
    
    mysql-test/include/commit.inc:
      Alter table rename was not committing the normal transaction at the
      end of its execution, and as a consequence, the commit was being
      issued in the next DDL command (rename table) that happened to end
      the active transaction. Other changes are to take into account the
      implicit commits issued before and after the DDL command execution.
    mysql-test/include/implicit_commit_helper.inc:
      Add auxiliary test that shows if a statement issued a 
      implicit commit.
    mysql-test/r/commit_1innodb.result:
      
      Update test case result.
    mysql-test/r/implicit_commit.result:
      Test implicit commit behavior of some SQL commands.
    mysql-test/t/implicit_commit.test:
      Test implicit commit behavior of some SQL commands.
    sql/events.cc:
      Transaction is now ended before the command execution.
    sql/mysql_priv.h:
      Add flags array for server commands and remove historical 
      left over.
    sql/sql_class.h:
      Add flags to control when to issue implicit commits before and
      after a command execution.
    sql/sql_delete.cc:
      A implicit commit is issued at the end of truncate
      statements.
    sql/sql_parse.cc:
      Mark commands that need implicit commits before and
      after their executions. The implicit commits of the
      statement and the normal transaction are now issued
      regardless of the user access privileges.
    sql/sql_table.cc:
      A implicit commit is now issued before admin commands.
    tests/mysql_client_test.c:
      Test that COM_REFRESH issues a implicit commit.
    c34ac8ee
commit_1innodb.result 19.1 KB