the join is "left out join"
James Pang 於 2024年7月3日週三 下午2:51寫道：
>
> the query is
>select
>from table b join table aa
>on b.partitionkeyid=aa.partitionkeyid
>where b.id1= $1 and b.id2=$2 and b.rtime between $3 and $4;
>
> looks like optimizer try to "calcul
the query is
select
from table b join table aa
on b.partitionkeyid=aa.partitionkeyid
where b.id1= $1 and b.id2=$2 and b.rtime between $3 and $4;
looks like optimizer try to "calculate cost for nestloop for
scanning all partitions of tablexxx (32 hash partitions) "
Both tables are hash partition tables , and we have a left out join ,
optimizer convert to Hash Right Join, but it always try to seq scan on
tablexxx 32 paritions. there are almost 250k rows per parition for
table , so it's slow. As a workaround, I disable hashjoin the it run
much fast with
