db2isolationlevels.out

derby database source code.good for you.

CS  
ij> select * from t1 with RR;
C1         
-----------
1          
ij> values SYSCS_UTIL.SYSCS_GET_RUNTIMESTATISTICS();
1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Statement Name: 
	null
Statement Text: 
	select * from t1 with RR
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: 
Index Scan ResultSet for T1 using constraint ASDF at serializable isolation level using share table locking chosen by the optimizer
Number of opens = 1
Rows seen = 1
Rows filtered = 0
Fetch Size = 16
	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}
	Number of columns fetched=1
	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: 
	None
	stop position: 
	None
	qualifiers:
None
ij> set isolation serializable;
0 rows inserted/updated/deleted
ij> execute getIsolation;
1   
----
RR  
ij> select * from t1 with RS;
C1         
-----------
1          
ij> values SYSCS_UTIL.SYSCS_GET_RUNTIMESTATISTICS();
1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Statement Name: 
	null
Statement Text: 
	select * from t1 with RS
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: 
Index Scan ResultSet for T1 using constraint ASDF at repeatable read isolation level using share row locking chosen by the optimizer
Number of opens = 1
Rows seen = 1
Rows filtered = 0
Fetch Size = 16
	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}
	Number of columns fetched=1
	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: 
	None
	stop position: 
	None
	qualifiers:
None
ij> set current isolation to read committed;
0 rows inserted/updated/deleted
ij> execute getIsolation;
1   
----
CS  
ij> select * from t1 with ur;
C1         
-----------
1          
ij> values SYSCS_UTIL.SYSCS_GET_RUNTIMESTATISTICS();
1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Statement Name: 
	null
Statement Text: 
	select * from t1 with ur
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: 
Index Scan ResultSet for T1 using constraint ASDF at read uncommitted isolation level using share row locking chosen by the optimizer
Number of opens = 1
Rows seen = 1
Rows filtered = 0
Fetch Size = 16
	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}
	Number of columns fetched=1
	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: 
	None
	stop position: 
	None
	qualifiers:
None
ij> -- unknown isolation level
select * from t1 with rw;
ERROR 42X01: Syntax error: Encountered "rw" at line 2, column 23.
ij> select * from t1 with DIRTY READ;
ERROR 42X01: Syntax error: Encountered "DIRTY" at line 1, column 23.
ij> select * from t1 with READ UNCOMMITTED;
ERROR 42X01: Syntax error: Encountered "READ" at line 1, column 23.
ij> select * from t1 with READ COMMITTED;
ERROR 42X01: Syntax error: Encountered "READ" at line 1, column 23.
ij> select * from t1 with CURSOR STABILITY;
ERROR 42X01: Syntax error: Encountered "CURSOR" at line 1, column 23.
ij> select * from t1 with REPEATABLE READ;
ERROR 42X01: Syntax error: Encountered "REPEATABLE" at line 1, column 23.
ij> select * from t1 with SERIALIZABLE;
ERROR 42X01: Syntax error: Encountered "SERIALIZABLE" at line 1, column 23.
ij> -- check the db2 isolation levels can be used as identifiers
create table db2iso(cs int, rr int, ur int, rs int);
0 rows inserted/updated/deleted
ij> select cs, rr, ur, rs from db2iso;
CS         |RR         |UR         |RS         
-----------------------------------------------
ij> -- cleanup
drop table t1;
0 rows inserted/updated/deleted
ij>