About deadlock for drop index command on big size table

[emilu]

Hello,

I tried to call drop index on a big table(around 3 million records)  
through non-multi thread script, and got deadlock.


Same drop index command in the same script on a smaller size table no  
deadlock returned.


May I know that may cause the problem please?

Thanks a lot.

[Block info]
 blocking_pid | blocked_pid | blocked_query
--+-+---
 123 | 7298 | DROP index idx1
 123 | 7298 | DROP index idx1

psql12.3 + jdbc_fdw - return wrong query results by using OR

[emilu]

Hello,

psql12.3 + jdbc_fdw(oracle18.x), tried:

[1]
select count(*)
from oracle_t1 as a
inner join local_t1 as b
on (a.c1 = b.c1);

return 100 records

[2]
select count(*)
from oracle_t1 as a
inner join local_t1 as b
on (a.c1 = b.c1
OR
a.c2 = b.c1
   );

return only 2 records

(no null values in both tables.)

May I know what may cause the error please?

Thanks a lot.