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26.4.5 Pre-Filtering by Object
The setup_objects
table controls
whether the Performance Schema monitors particular table and
stored program objects. The initial
setup_objects
contents look like
this:
- +-------------+--------------------+-------------+---------+-------+
- | OBJECT_TYPE | OBJECT_SCHEMA | OBJECT_NAME | ENABLED | TIMED |
- +-------------+--------------------+-------------+---------+-------+
- | EVENT | % | % | YES | YES |
- +-------------+--------------------+-------------+---------+-------+
Modifications to the setup_objects
table affect object monitoring immediately.
The OBJECT_TYPE
column indicates the type of
object to which a row applies. TABLE
filtering affects table I/O events
(wait/io/table/sql/handler
instrument) and
table lock events
(wait/lock/table/sql/handler
instrument).
The OBJECT_SCHEMA
and
OBJECT_NAME
columns should contain a literal
schema or object name, or '%'
to match any
name.
The ENABLED
column indicates whether matching
objects are monitored, and TIMED
indicates
whether to collect timing information. Setting the
TIMED
column affects Performance Schema table
contents as described in
Section 26.4.1, “Performance Schema Event Timing”.
The effect of the default object configuration is to instrument
all objects except those in the mysql
,
INFORMATION_SCHEMA
, and
performance_schema
databases. (Tables in the
INFORMATION_SCHEMA
database are not
instrumented regardless of the contents of
setup_objects
; the row for
information_schema.%
simply makes this
default explicit.)
When the Performance Schema checks for a match in
setup_objects
, it tries to find
more specific matches first. For rows that match a given
OBJECT_TYPE
, the Performance Schema checks
rows in this order:
Rows with
OBJECT_SCHEMA='
andliteral
'OBJECT_NAME='
.literal
'Rows with
OBJECT_SCHEMA='
andliteral
'OBJECT_NAME='%'
.Rows with
OBJECT_SCHEMA='%'
andOBJECT_NAME='%'
.
For example, with a table db1.t1
, the
Performance Schema looks in TABLE
rows for a
match for 'db1'
and 't1'
,
then for 'db1'
and '%'
,
then for '%'
and '%'
. The
order in which matching occurs matters because different
matching setup_objects
rows can
have different ENABLED
and
TIMED
values.
For table-related events, the Performance Schema combines the
contents of setup_objects
with
setup_instruments
to determine
whether to enable instruments and whether to time enabled
instruments:
For tables that match a row in
setup_objects
, table instruments produce events only ifENABLED
isYES
in bothsetup_instruments
andsetup_objects
.The
TIMED
values in the two tables are combined, so that timing information is collected only when both values areYES
.
For stored program objects, the Performance Schema takes the
ENABLED
and TIMED
columns
directly from the setup_objects
row. There is no combining of values with
setup_instruments
.
Suppose that setup_objects
contains
the following TABLE
rows that apply to
db1
, db2
, and
db3
:
- +-------------+---------------+-------------+---------+-------+
- | OBJECT_TYPE | OBJECT_SCHEMA | OBJECT_NAME | ENABLED | TIMED |
- +-------------+---------------+-------------+---------+-------+
- +-------------+---------------+-------------+---------+-------+
If an object-related instrument in
setup_instruments
has an
ENABLED
value of NO
,
events for the object are not monitored. If the
ENABLED
value is YES
,
event monitoring occurs according to the
ENABLED
value in the relevant
setup_objects
row:
db1.t1
events are monitoreddb1.t2
events are not monitoreddb2.t3
events are monitoreddb3.t4
events are not monitoreddb4.t5
events are monitored
Similar logic applies for combining the TIMED
columns from the setup_instruments
and setup_objects
tables to
determine whether to collect event timing information.
If a persistent table and a temporary table have the same name,
matching against setup_objects
rows
occurs the same way for both. It is not possible to enable
monitoring for one table but not the other. However, each table
is instrumented separately.
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Document créé le 26/06/2006, dernière modification le 26/10/2018
Source du document imprimé : https://www.gaudry.be/mysql-rf-performance-schema-object-filtering.html
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