(JP) timestamp型の比較を行うSQL文の実行結果が正しくないことがある

[taiki-k]

最新のコードで以下のSQL文を実行したところと、結果が0 rowsとなりました。
SeqScanで行うと、5 rowsが表示されます。

• 実行したSQL文

SELECT * FROM temperature_tokyo WHERE high - low >= 15 AND high_time < low_time;

• 結果(GPU)

pgstrom_test=#  explain select * from temperature_tokyo where high - low >= 15 and high_time < low_time;
                                      QUERY PLAN
--------------------------------------------------------------------------------------
 Custom (GpuScan) on temperature_tokyo  (cost=10000.00..10048.05 rows=609 width=28)
   Host References: date, high, high_time, low, low_time
   Device References: high, high_time, low, low_time
   Device Filter: ((high_time < low_time) AND ((high - low) >= 15::double precision))
 Planning time: 0.335 ms
(5 rows)

pgstrom_test=# select * from temperature_tokyo where high - low >= 15 and high_time < low_time;
INFO:  now building tcache...
INFO:  tcache build done...
 date | high | high_time | low | low_time
------+------+-----------+-----+----------
(0 rows)

• 結果(SeqScan)

pgstrom_test=#  explain select * from temperature_tokyo where high - low >= 15 and high_time < low_time;
                                  QUERY PLAN
-------------------------------------------------------------------------------
 Seq Scan on temperature_tokyo  (cost=0.00..136.88 rows=609 width=28)
   Filter: ((high_time < low_time) AND ((high - low) >= 15::double precision))
 Planning time: 0.242 ms
(3 rows)

pgstrom_test=# select * from temperature_tokyo where high - low >= 15 and high_time < low_time;
    date    | high |      high_time      | low  |      low_time
------------+------+---------------------+------+---------------------
 2001-04-03 | 22.5 | 2001-04-03 13:38:00 |  7.3 | 2001-04-03 23:47:00
 2003-05-08 | 26.9 | 2003-05-08 11:11:00 | 11.3 | 2003-05-09 00:00:00
 2008-02-23 |   17 | 2008-02-23 13:06:00 |  0.7 | 2008-02-24 00:00:00
 2008-12-22 | 19.9 | 2008-12-22 10:17:00 |  4.2 | 2008-12-22 20:20:00
 2013-03-10 | 25.3 | 2013-03-10 13:10:00 |  5.7 | 2013-03-10 23:58:00
(5 rows)

• 対象のテーブル

          Table "public.temperature_tokyo"
  Column   |            Type             | Modifiers
-----------+-----------------------------+-----------
 date      | date                        |
 high      | real                        |
 high_time | timestamp without time zone |
 low       | real                        |
 low_time  | timestamp without time zone |

WHERE句の "high - low >= 15" の条件がない場合は、正しい結果が出力されるように見えます。

[taiki-k]

nVidiaのほうで試したところ、こちらはAssertion Failedとなりました。

• バックトレース

#0  0x0000003cdbc32925 in raise () from /lib64/libc.so.6
#1  0x0000003cdbc3408d in abort () from /lib64/libc.so.6
#2  0x0000000000949085 in ExceptionalCondition (conditionName=0x7fab3123c2c1 "!(rc == 0)",
    errorType=0x7fab3123b884 "FailedAssertion", fileName=0x7fab3123b8ad "gpuscan.c", lineNumber=2269) at assert.c:54
#3  0x00007fab31224138 in clserv_respond_gpuscan_column (event=0x7faa84bc0e80, ev_status=0, private=0x7faa84845930) at gpuscan.c:2269
#4  0x00007faaa6eeb283 in ?? () from /usr/lib64/libnvidia-opencl.so.1
#5  0x00007faaa6eefa73 in ?? () from /usr/lib64/libnvidia-opencl.so.1
#6  0x00007faaa6ef01e4 in ?? () from /usr/lib64/libnvidia-opencl.so.1
#7  0x00007faaa767bf89 in ?? () from /usr/lib64/libnvidia-opencl.so.1
#8  0x0000003cdc0079d1 in start_thread () from /lib64/libpthread.so.0
#9  0x0000003cdbce8b6d in clone () from /lib64/libc.so.6

[kaigai]

#23と同根かと思います。こちらも最新版をpullして再現確認をお願いします。

[taiki-k]

最新版で再現確認を行ったところ、再現しなくなりました。
修正されたものと判断します。