- The basic tree structure:
- plan: The root of the XML tree
- statement: First child, the query executed
- time: Second child, the time that this query executed
- stmt_id : Third child, the STMT_ID of the query
- details: Fourth child, containing the query plan
- The statement element:
This element has only its value. That value implies the query executed, as
retrieved from the STMT_TEXT row of the SYSXPLAIN_STATEMENTS table.
For example:
<statement>select * from my_table</statement>
- The time element:
This element has only its value. That value implies the date and time when
the query executed, as retrieved from the XPLAIN_TIME row of the
SYSXPLAIN_STATEMENTS table.
For example:
<time>2010-07-13 14:27:59.405</time>
- The stmt_id element:
This element has only its value. That value implies the statement ID of the
query executed, as retrieved from the STMT_ID row of the SYSXPLAIN_STATEMENTS
table.
For example:
<stmt_id>9ac8804c-0129-cc31-ca9a-00000047f1e8</stmt_id>
- The details element:
This element contains the query plan, as a tree structure of plan nodes.
For a particular query there is only one root plan node.
- A node element:
Contains the details of a plan node of the query plan. This element can
contain zero or many child elements of the same type (node
elements).
This element contains one or more attributes, given that they are not null.
The possible attributes and their meanings are shown in the following table.
Attributes of the node element
This table lists and describes the attributes of the node element.
Attribute Name
Meaning
name
Name of the plan node
input_rows
Retrieved from the INPUT_ROWS row of the
SYSXPLAIN_RESULTSETS system table
returned_rows
Retrieved from the RETURNED_ROWS row of the
SYSXPLAIN_RESULTSETS system table
no_opens
Retrieved from the NO_OPENS row of the
SYSXPLAIN_RESULTSETS system table
visited_pages
Retrieved from the NO_VISITED_PAGES row of the
SYSXPLAIN_SCAN_PROPS system table
scan_qualifiers
Retrieved from the SCAN_QUALIFIERS row of the
SYSXPLAIN_SCAN_PROPS system table
next_qualifiers
Retrieved from the NEXT_QUALIFIERS row of the
SYSXPLAIN_SCAN_PROPS system table
scanned_object
Retrieved from the SCAN_OBJECT_NAME row of the
SYSXPLAIN_SCAN_PROPS system table
scan_type
Retrieved from the SCAN_TYPE row of the
SYSXPLAIN_SCAN_PROPS system table
sort_type
Retrieved from the SORT_TYPE row of the
SYSXPLAIN_SORT_PROPS system table
sorter_output
Retrieved from the NO_OUTPUT_ROWS row of the
SYSXPLAIN_SORT_PROPS system table
For example:
<node name="TABLESCAN" returned_rows="100000" no_opens="1"
visited_pages="2165" scan_qualifiers="None" scanned_object="USERS"
scan_type="HEAP">