Hello!
I like heapam verification functionality and use it right now. So, I'm planning
to provide review for this patch, probably, this week.
From my current use I have some thoughts on interface. Here's what I get.
# select bt_index_check('messagefiltervalue_group_id_59490523e6ee451f',true);
ERROR: XX001: heap tuple (45,21) from table "messagefiltervalue" lacks
matching index tuple within index "messagefiltervalue_group_id_59490523e6ee451f"
HINT: Retrying verification using the function bt_index_parent_check() might
provide a more specific error.
LOCATION: bt_tuple_present_callback, verify_nbtree.c:1316
Time: 45.668 ms
# select bt_index_check('messagefiltervalue_group_id_59490523e6ee451f');
bt_index_check
----------------
(1 row)
Time: 32.873 ms
# select bt_index_parent_check('messagefiltervalue_group_id_59490523e6ee451f');
ERROR: XX002: down-link lower bound invariant violated for index
"messagefiltervalue_group_id_59490523e6ee451f"
DETAIL: Parent block=6259 child index tid=(1747,2) parent page
lsn=4A0/728F5DA8.
LOCATION: bt_downlink_check, verify_nbtree.c:1188
Time: 391194.113 ms
Seems like new check is working 4 orders of magnitudes faster then
bt_index_parent_check() and still finds my specific error that bt_index_check()
missed.
From this output I see that there is corruption, but cannot understand:
1. What is the scale of corruption
2. Are these corruptions related or not
I think an interface to list all or top N error could be useful.
> 14 дек. 2017 г., в 0:02, Peter Geoghegan <p...@bowt.ie> написал(а):
>>
>> This could also test the reproducibility of the tests with a fixed
>> seed number and at least two rounds, a low number of elements could be
>> more appropriate to limit the run time.
>
> The runtime is already dominated by pg_regress overhead. As it says in
> the README, using a fixed seed in the test harness is pointless,
> because it won't behave in a fixed way across platforms. As long as we
> cannot ensure deterministic behavior, we may as well fully embrace
> non-determinism.
I think that determinism across platforms is not that important as determinism
across runs.
Thanks for the amcheck! It is very useful.
Best regards, Andrey Borodin.
