aggregateoptimization.out

derby database source code.good for you.

Statement Text: 
	-- equality predicates on all key columns preceding min column, 
-- a unique index
select min(c2) from t1 where c1 = 1
Parse Time: 0
Bind Time: 0
Optimize Time: 0
Generate Time: 0
Compile Time: 0
Execute Time: 0
Begin Compilation Timestamp : null
End Compilation Timestamp : null
Begin Execution Timestamp : null
End Execution Timestamp : null
Statement Execution Plan Text: 
Project-Restrict ResultSet (5):
Number of opens = 1
Rows seen = 1
Rows filtered = 0
restriction = false
projection = true
	constructor time (milliseconds) = 0
	open time (milliseconds) = 0
	next time (milliseconds) = 0
	close time (milliseconds) = 0
	restriction time (milliseconds) = 0
	projection time (milliseconds) = 0
Source result set:
	Scalar Aggregate ResultSet:
	Number of opens = 1
	Rows input = 1
		constructor time (milliseconds) = 0
		open time (milliseconds) = 0
		next time (milliseconds) = 0
		close time (milliseconds) = 0
	Index Key Optimization = true
	Source result set:
		Project-Restrict ResultSet (4):
		Number of opens = 1
		Rows seen = 1
		Rows filtered = 0
		restriction = false
		projection = true
			constructor time (milliseconds) = 0
			open time (milliseconds) = 0
			next time (milliseconds) = 0
			close time (milliseconds) = 0
			restriction time (milliseconds) = 0
			projection time (milliseconds) = 0
		Source result set:
			Index Row to Base Row ResultSet for T1:
			Number of opens = 1
			Rows seen = 1
			Columns accessed from heap = {1}
				constructor time (milliseconds) = 0
				open time (milliseconds) = 0
				next time (milliseconds) = 0
				close time (milliseconds) = 0
				Index Scan ResultSet for T1 using index I1 at serializable isolation level using share row locking chosen by the optimizer
				Number of opens = 1
				Rows seen = 1
				Rows filtered = 0
				Fetch Size = 1
					constructor time (milliseconds) = 0
					open time (milliseconds) = 0
					next time (milliseconds) = 0
					close time (milliseconds) = 0
					next time in milliseconds/row = 0
				scan information: 
					Bit set of columns fetched=All
					Number of columns fetched=2
					Number of deleted rows visited=0
					Number of pages visited=1
					Number of rows qualified=1
					Number of rows visited=1
					Scan type=btree
					Tree height=1
					start position: 
	>= on first 1 column(s).
	Ordered null semantics on the following columns: 
					stop position: 
	> on first 1 column(s).
	Ordered null semantics on the following columns: 
					qualifiers:
None
ij> -- group by ordered on grouping columns
create table t2(c1 int, c2 int, c3 int, c4 int);
0 rows inserted/updated/deleted
ij> create index t2_i1 on t2(c1);
0 rows inserted/updated/deleted
ij> create index t2_i2 on t2(c1, c2);
0 rows inserted/updated/deleted
ij> -- empty table
select c1, sum(c2) from t2 group by c1;
C1         |2          
-----------------------
ij> values SYSCS_UTIL.SYSCS_GET_RUNTIMESTATISTICS();
1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Statement Name: 
	null
Statement Text: 
	-- empty table
select c1, sum(c2) from t2 group by c1
Parse Time: 0
Bind Time: 0
Optimize Time: 0
Generate Time: 0
Compile Time: 0
Execute Time: 0
Begin Compilation Timestamp : null
End Compilation Timestamp : null
Begin Execution Timestamp : null
End Execution Timestamp : null
Statement Execution Plan Text: 
Project-Restrict ResultSet (4):
Number of opens = 1
Rows seen = 0
Rows filtered = 0
restriction = false
projection = true
	constructor time (milliseconds) = 0
	open time (milliseconds) = 0
	next time (milliseconds) = 0
	close time (milliseconds) = 0
	restriction time (milliseconds) = 0
	projection time (milliseconds) = 0
Source result set:
	Grouped Aggregate ResultSet:
	Number of opens = 1
	Rows input = 0
	Has distinct aggregate = false
	In sorted order = true
		constructor time (milliseconds) = 0
		open time (milliseconds) = 0
		next time (milliseconds) = 0
		close time (milliseconds) = 0
	Source result set:
		Project-Restrict ResultSet (3):
		Number of opens = 1
		Rows seen = 0
		Rows filtered = 0
		restriction = false
		projection = true
			constructor time (milliseconds) = 0
			open time (milliseconds) = 0
			next time (milliseconds) = 0
			close time (milliseconds) = 0
			restriction time (milliseconds) = 0
			projection time (milliseconds) = 0
		Source result set:
			Index Scan ResultSet for T2 using index T2_I2 at serializable isolation level using share table locking chosen by the optimizer
			Number of opens = 1
			Rows seen = 0
			Rows filtered = 0
			Fetch Size = 1
				constructor time (milliseconds) = 0
				open time (milliseconds) = 0
				next time (milliseconds) = 0
				close time (milliseconds) = 0
			scan information: 
				Bit set of columns fetched={0, 1}
				Number of columns fetched=2
				Number of deleted rows visited=0
				Number of pages visited=1
				Number of rows qualified=0
				Number of rows visited=0
				Scan type=btree
				Tree height=1
				start position: 
	None
				stop position: 
	None
				qualifiers:
None
ij> -- 1 row table
insert into t2 values (1, 1, 1, 1);
1 row inserted/updated/deleted
ij> select c1, sum(c2) from t2 group by c1;
C1         |2          
-----------------------
1          |1          
ij> values SYSCS_UTIL.SYSCS_GET_RUNTIMESTATISTICS();
1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Statement Name: 
	null
Statement Text: 
	select c1, sum(c2) from t2 group by c1
Parse Time: 0
Bind Time: 0
Optimize Time: 0
Generate Time: 0
Compile Time: 0
Execute Time: 0
Begin Compilation Timestamp : null
End Compilation Timestamp : null
Begin Execution Timestamp : null
End Execution Timestamp : null
Statement Execution Plan Text: 
Project-Restrict ResultSet (4):
Number of opens = 1
Rows seen = 1
Rows filtered = 0
restriction = false
projection = true
	constructor time (milliseconds) = 0
	open time (milliseconds) = 0
	next time (milliseconds) = 0
	close time (milliseconds) = 0
	restriction time (milliseconds) = 0
	projection time (milliseconds) = 0
Source result set:
	Grouped Aggregate ResultSet:
	Number of opens = 1
	Rows input = 1
	Has distinct aggregate = false
	In sorted order = true
		constructor time (milliseconds) = 0
		open time (milliseconds) = 0
		next time (milliseconds) = 0
		close time (milliseconds) = 0
	Source result set:
		Project-Restrict ResultSet (3):
		Number of opens = 1
		Rows seen = 1
		Rows filtered = 0
		restriction = false
		projection = true
			constructor time (milliseconds) = 0
			open time (milliseconds) = 0
			next time (milliseconds) = 0
			close time (milliseconds) = 0
			restriction time (milliseconds) = 0
			projection time (milliseconds) = 0
		Source result set:
			Index Scan ResultSet for T2 using index T2_I2 at serializable isolation level using share table locking chosen by the optimizer
			Number of opens = 1
			Rows seen = 1
			Rows filtered = 0
			Fetch Size = 1
				constructor time (milliseconds) = 0
				open time (milliseconds) = 0
				next time (milliseconds) = 0
				close time (milliseconds) = 0
				next time in milliseconds/row = 0
			scan information: 
				Bit set of columns fetched={0, 1}
				Number of columns fetched=2