TAJO-922: Add NTH_VALUE window function

[ghost]

merged master branch.

[sirpkt]

It looks good overall to me, however it seems to contain the code for ntile function also.
Would you clean up the patch to include code related to nth_value only, @seungunchoe?

[jihoonson]

The test code is missed.

[hyunsik]

@jihoonson Are there something more to do?

[jihoonson]

This file looks not to be included in this patch.

[jihoonson]

Sorry for late response.
I've found query result looks wrong as follows.
Tajo

tpch> select n_regionkey, nth_value(n_comment, 1) over (partition by n_regionkey) from nation;
Progress: 100%, response time: 0.314 sec
n_regionkey,  ?windowfunction
-------------------------------
0,  rns. blithely bold courts among the closely regular packages use furiously bold platelets?
0,  rns. blithely bold courts among the closely regular packages use furiously bold platelets?
0,  rns. blithely bold courts among the closely regular packages use furiously bold platelets?
0,  rns. blithely bold courts among the closely regular packages use furiously bold platelets?
0,  rns. blithely bold courts among the closely regular packages use furiously bold platelets?
1,  y final packages. slow foxes cajole quickly. quickly silent platelets breach ironic accounts. unusual pinto be
1,  y final packages. slow foxes cajole quickly. quickly silent platelets breach ironic accounts. unusual pinto be
1,  y final packages. slow foxes cajole quickly. quickly silent platelets breach ironic accounts. unusual pinto be
1,  y final packages. slow foxes cajole quickly. quickly silent platelets breach ironic accounts. unusual pinto be
1,  y final packages. slow foxes cajole quickly. quickly silent platelets breach ironic accounts. unusual pinto be
2,  ously. final, express gifts cajole a
2,  ously. final, express gifts cajole a
2,  ously. final, express gifts cajole a
2,  ously. final, express gifts cajole a
2,  ously. final, express gifts cajole a
3,  refully final requests. regular, ironi
3,  refully final requests. regular, ironi
3,  refully final requests. regular, ironi
3,  refully final requests. regular, ironi
3,  refully final requests. regular, ironi
4,  y above the carefully unusual theodolites. final dugouts are quickly across the furiously regular d
4,  y above the carefully unusual theodolites. final dugouts are quickly across the furiously regular d
4,  y above the carefully unusual theodolites. final dugouts are quickly across the furiously regular d
4,  y above the carefully unusual theodolites. final dugouts are quickly across the furiously regular d
4,  y above the carefully unusual theodolites. final dugouts are quickly across the furiously regular d
(25 rows, 0.314 sec, 1.9 KiB selected)

Pgsql

postgres=# select n_regionkey, nth_value(n_comment, 1) over (partition by n_regionkey) from nation;
 n_regionkey |                                                    nth_value                                                    
-------------+-----------------------------------------------------------------------------------------------------------------
           0 | ven packages wake quickly. regu
           0 | ven packages wake quickly. regu
           0 | ven packages wake quickly. regu
           0 | ven packages wake quickly. regu
           0 | ven packages wake quickly. regu
           1 | y final packages. slow foxes cajole quickly. quickly silent platelets breach ironic accounts. unusual pinto be
           1 | y final packages. slow foxes cajole quickly. quickly silent platelets breach ironic accounts. unusual pinto be
           1 | y final packages. slow foxes cajole quickly. quickly silent platelets breach ironic accounts. unusual pinto be
           1 | y final packages. slow foxes cajole quickly. quickly silent platelets breach ironic accounts. unusual pinto be
           1 | y final packages. slow foxes cajole quickly. quickly silent platelets breach ironic accounts. unusual pinto be
           2 | hely enticingly express accounts. even, final 
           2 | hely enticingly express accounts. even, final 
           2 | hely enticingly express accounts. even, final 
           2 | hely enticingly express accounts. even, final 
           2 | hely enticingly express accounts. even, final 
           3 | ular asymptotes are about the furious multipliers. express dependencies nag above the ironically ironic account
           3 | ular asymptotes are about the furious multipliers. express dependencies nag above the ironically ironic account
           3 | ular asymptotes are about the furious multipliers. express dependencies nag above the ironically ironic account
           3 | ular asymptotes are about the furious multipliers. express dependencies nag above the ironically ironic account
           3 | ular asymptotes are about the furious multipliers. express dependencies nag above the ironically ironic account
           4 | y above the carefully unusual theodolites. final dugouts are quickly across the furiously regular d
           4 | y above the carefully unusual theodolites. final dugouts are quickly across the furiously regular d
           4 | y above the carefully unusual theodolites. final dugouts are quickly across the furiously regular d
           4 | y above the carefully unusual theodolites. final dugouts are quickly across the furiously regular d
           4 | y above the carefully unusual theodolites. final dugouts are quickly across the furiously regular d
(25 rows)