DB2 10.5 for Linux, UNIX, and Windows

EXPLAIN_FORMAT_OUTPUT table

When db2exfmt utility formats explain tables, its output sometimes contains symbols around operators.

The following tables list the various symbols that are used with the operators of the ASCII explain graph.

Table 1. Symbols used with JOIN operator
Character before operator	Character after operator	Equivalent Explain argument	Argument value	Description
>		OUTERJN	LEFT	Left outer join
	<	OUTERJN	RIGHT	Right outer join
>	<	OUTERJN	FULL	Full outer join
x		OUTERJN	LEFT (ANTI)	Left outer anti-join
	x	OUTERJN	RIGHT (ANTI)	Right outer anti-join
^		EARLYOUT	LEFT	Left early out
	^	EARLYOUT	RIGHT	Right early out

Table 2. Symbols used with TQ operator
Character before operator	Character after operator	Equivalent Explain argument	Argument value	Description
A		TQORIGIN	ASYNCHRONY	Table queue that is used for asynchrony
B		TQSEND	BROADCAST	All rows sent to all receiving database partitions
C		TQORIGIN	'COLUMN-ORGANIZED DATA' or 'ROW-ORGANIZED DATA'	Represents the transition between column-organized data processing and row-organized data processing
D		TQSEND	DIRECTED	Rows are hashed to each of the receiving database partitions by using the table queue 's partitioning key
L		TQTYPE	LOCAL	Intra-partition parallelism
M		TQMERGE	TRUE	Merging (sorted) table queue
X		TQORIGIN	XML AGG TQ	Table queue that is used for XML aggregation
S		TQSEND	SCATTER	Rows are scattered to receiving database partitions without using a partitioning key
	*	LISTENER	TRUE	Table queue waits to receive values from other database partitions

Table 3. Unique symbols per key
Character before operator	Operator	Equivalent Explain argument	Argument value	Description
p	UNIQUE	UNIQUE	HASHED PARTIAL	Partial early aggregation
p	GRPBY	AGGMODE	HASHED PARTIAL	Per group aggregation
g	<many>	GROUPS		Multiple distinct processing