FOR EACH {ROW | STATEMENT} 

CREATE TRIGGER <Trigger name>
{BEFORE | AFTER} <trigger event> ON <Table name>
[ REFERENCING <old or new values alias list> ]
<triggered action>

   <trigger event> ::=
   INSERT |
   DELETE |
   UPDATE [ OF <trigger Column list> ]

      <trigger Column list> ::= <Column name> [ {,<Column name>} ... ]

   <old or new values alias list> ::=
   <old or new values alias>...

      <old or new values alias> ::=
      OLD [ ROW ] [ AS ] old values <Correlation name> |
      NEW [ ROW ] [ AS ] new values <Correlation name> |
      OLD TABLE [ AS ] <old values Table alias> |
      NEW TABLE [ AS ] <new values Table alias>

         <old values Table alias> ::= <identifier>

         <new values Table alias> ::= <identifier>

   <triggered action> ::=
   [ FOR EACH {ROW | STATEMENT} ] [ WHEN (search condition) ]
      <triggered SQL statement>

      <triggered SQL statement> ::=
      SQL statement |
      BEGIN ATOMIC {SQL statement;}... END

innodb_flush_method

Description: XtraDB/InnoDB flushing method. Windows always uses async_unbuffered and this variable then has no effect. On Unix, by default fsync() is used to flush data and logs. Adjusting this variable can give performance improvements, but behavior differs widely on different filesystems, and changing from the default has caused problems in some situations, so test and benchmark carefully before adjusting.
O_DSYNC - O_DSYNC is used to open and flush logs, and fsync() to flush the data files.
O_DIRECT - O_DIRECT or directio(), is used to open data files, and fsync() to flush data and logs.
fdatasync - an old default value that follows the default behavior of using fsync(), but replaced with the unset default to avoid confusion between fdatasync() and fysnc().
O_DIRECT_NO_FSYNC - introduced in MariaDB 10.0 / MySQL 5.6.7. Uses O_DIRECT during flushing I/O, but skips fsync() afterwards. Not suitable for XFS filesystems.
Commandline: --innodb-flush-method=name
Scope: Global
Dynamic: No
Data Type: enumeration
Default Value: Not set.
Valid Values: fdatasync, O_DSYNC, O_DIRECT, O_DIRECT_NO_FSYNC (MariaDB 10.0)