readcursorlocks.subsql

derby database source code.good for you.

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

close scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

commit;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;
commit;

--------------------------------------------------------------------------------
-- TEST 5: heap cursor scan, group fetch = 2 (scan with committed deleted rows)
-- Test full cursor scan on a data set with some deleted rows (the "even" ones).
--    SERIALIZABLE     - will get table level S lock.
--    REPEATABLE READ  - TABLE IS, will get row S locks as it visits each row 
--                        (including deleted ones).
--    READ COMMITTED   - TABLE IS, will get instantaneous locks and release
--    READ UNCOMMITTED - TABLE IS, no row locks.
--
-- At this point the table should look like:
-- 1, 10, 'one'
-- 3, 30, 'three'
-- 5, 50, 'five'
-- 7, 70, 'seven'
--------------------------------------------------------------------------------

CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY('derby.language.bulkFetchDefault','2');

-- RESOLVE: missing row locks
-- WORKAROUND: creating an index and dropping it 
-- to force the query 'select a, b, c from a' to be recompiled
create index ix1 on a(a);
drop index ix1;
commit;

get cursor scan_cursor as
    'select a, b, c from a';
call SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY('derby.language.bulkFetchDefault', '16');

select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

close scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

commit;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;
commit;

--------------------------------------------------------------------------------
-- TEST 6: heap cursor scan, group fetch = 1 (scan with "<" qualifier)
-- Test "less than" qualified cursor scan on a data set.
--    SERIALIZABLE     - will get table level S lock.
--    REPEATABLE READ  - TABLE IS, will get row S locks as it visits each row 
--                        (including deleted ones).
--    READ COMMITTED   - TABLE IS, will get instantaneous locks and release
--    READ UNCOMMITTED - TABLE IS, no row locks.
--
-- At this point the table should look like:
-- 1, 10, 'one'
-- 3, 30, 'three'
-- 5, 50, 'five'
-- 7, 70, 'seven'
--------------------------------------------------------------------------------

CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY('derby.language.bulkFetchDefault','1');
get cursor scan_cursor as
    'select a, b, c from a where a < 3';
call SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY('derby.language.bulkFetchDefault', '16');

select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

close scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

commit;

--------------------------------------------------------------------------------
-- TEST 7: heap cursor scan, group fetch = 2 (scan with "<" qualifier)
-- Test "less than" qualified cursor scan on a data set.
--    SERIALIZABLE     - will get table level S lock.
--    REPEATABLE READ  - TABLE IS, will get row S locks as it visits each row 
--                        (including deleted ones).
--    READ COMMITTED   - TABLE IS, will get instantaneous locks and release
--    READ UNCOMMITTED - TABLE IS, no row locks.
--
-- At this point the table should look like:
-- 1, 10, 'one'
-- 3, 30, 'three'
-- 5, 50, 'five'
-- 7, 70, 'seven'
--------------------------------------------------------------------------------

CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY('derby.language.bulkFetchDefault','2');

-- RESOLVE: missing row locks
-- WORKAROUND: creating an index and dropping it 
-- to force the statement to be recompiled
create index ix1 on a(a);
drop index ix1;
commit;

get cursor scan_cursor as
    'select a, b, c from a where a < 3';
call SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY('derby.language.bulkFetchDefault', '16');

select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

close scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

commit;

--------------------------------------------------------------------------------
-- TEST 8: heap cursor scan, group fetch = 1 (scan with equals qualifier)
-- Test "equals" qualified cursor scan on a data set.
--    SERIALIZABLE     - will get table level S lock.
--    REPEATABLE READ  - TABLE IS, will get row S locks as it visits each row 
--                        (including deleted ones).
--    READ COMMITTED   - TABLE IS, will get instantaneous locks and release
--    READ UNCOMMITTED - TABLE IS, no row locks.
--
-- At this point the table should look like:
-- 1, 10, 'one'
-- 3, 30, 'three'
-- 5, 50, 'five'
-- 7, 70, 'seven'
--------------------------------------------------------------------------------

CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY('derby.language.bulkFetchDefault','1');
get cursor scan_cursor as
    'select a, b, c from a where a = 5';
call SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY('derby.language.bulkFetchDefault', '16');

select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

close scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

commit;

--------------------------------------------------------------------------------
-- TEST 9: heap cursor scan, group fetch = 2 (scan with equals qualifier)
-- Test "equals" qualified cursor scan on a data set.
--    SERIALIZABLE     - will get table level S lock.
--    REPEATABLE READ  - TABLE IS, will get row S locks as it visits each row 
--                        (including deleted ones).
--    READ COMMITTED   - TABLE IS, will get instantaneous locks and release
--    READ UNCOMMITTED - TABLE IS, no row locks.
--
-- At this point the table should look like:
-- 1, 10, 'one'
-- 3, 30, 'three'
-- 5, 50, 'five'
-- 7, 70, 'seven'
--------------------------------------------------------------------------------

CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY('derby.language.bulkFetchDefault','2');
get cursor scan_cursor as
    'select a, b, c from a where a = 7';
call SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY('derby.language.bulkFetchDefault', '16');

select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

close scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

commit;

--------------------------------------------------------------------------------
-- TEST 10: heap cursor scan, group fetch = 1 (equals qualifier, no rows return)
-- Test "equals" qualified cursor scan on a data set, no rows returned.
--    SERIALIZABLE     - will get table level S lock.
--    REPEATABLE READ  - TABLE IS, will get row S locks as it visits each row 
--                        (including deleted ones).
--    READ COMMITTED   - TABLE IS, will get instantaneous locks and release
--    READ UNCOMMITTED - TABLE IS, no row locks.
--
-- At this point the table should look like:
-- 1, 10, 'one'
-- 3, 30, 'three'
-- 5, 50, 'five'
-- 7, 70, 'seven'
--------------------------------------------------------------------------------

CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY('derby.language.bulkFetchDefault','1');

-- RESOLVE: missing row locks
-- WORKAROUND: creating an index and dropping it 
-- to force the statement to be recompiled
create index ix1 on a(a);
drop index ix1;
commit;

get cursor scan_cursor as
    'select a, b, c from a where a = 7';
CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY('derby.language.bulkFetchDefault','16');

select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

next scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

close scan_cursor;
select * from lock_table order by tabname, type desc, mode, cnt, lockname;

commit;

drop table a;