Performance Schema Instrument Naming Conventions-opracowanie

Performance Schema Instrument Naming Conventions
An instrument name consists of a sequence of components separated by '/' characters. Example
names:
wait/io/file/myisam/log
wait/io/file/mysys/charset
wait/lock/table/sql/handler
wait/synch/cond/mysys/COND_alarm
wait/synch/cond/sql/BINLOG::update_cond
wait/synch/mutex/mysys/BITMAP_mutex
wait/synch/mutex/sql/LOCK_delete
wait/synch/rwlock/sql/Query_cache_query::lock
stage/sql/closing tables
stage/sql/Sorting result
statement/com/Execute
statement/com/Query
statement/sql/create_table
statement/sql/lock_tables
The instrument name space has a tree-like structure. The components of an instrument name from left
to right provide a progression from more general to more specific. The number of components a name
has depends on the type of instrument.
The interpretation of a given component in a name depends on the components to the left of it. For
example, myisam appears in both of the following names, but myisam in the first name is related to file
I/O, whereas in the second it is related to a synchronization instrument:
wait/io/file/myisam/log
wait/synch/cond/myisam/MI_SORT_INFO::cond
Instrument names consist of a prefix with a structure defined by the Performance Schema
implementation and a suffix defined by the developer implementing the instrument code. The toplevel
component of an instrument prefix indicates the type of instrument. This component also
determines which event timer in the setup_timers table applies to the instrument. For the prefix part
of instrument names, the top level indicates the type of instrument.
The suffix part of instrument names comes from the code for the instruments themselves. Suffixes may
include levels such as these:
• A name for the major component (a server module such as myisam, innodb, mysys, or sql) or a
plugin name.
• The name of a variable in the code, in the form XXX (a global variable) or CCC::MMM (a member MMM
in class CCC). Examples: COND_thread_cache, THR_LOCK_myisam, BINLOG::LOCK_index.
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