On 2017/02/16 17:55, Amit Khandekar wrote: > On 16 February 2017 at 12:57, Amit Langote wrote: >> On 2017/02/16 15:50, Amit Khandekar wrote: >>> On 15 February 2017 at 20:26, David Fetter <da...@fetter.org> wrote: >>>> Does that make sense, and if so, is it super invasive to HINT that? >>> >>> Yeah, I think it should be possible to find the root partition with >> >> I assume you mean root *partitioned* table. >> >>> the help of pg_partitioned_table, >> >> The pg_partitioned_table catalog does not store parent-child >> relationships, just information about the partition key of a table. To >> get the root partitioned table, you might want to create a recursive >> version of get_partition_parent(), maybe called >> get_partition_root_parent(). By the way, get_partition_parent() scans >> pg_inherits to find the inheritance parent. > > Yeah. But we also want to make sure that it's a part of declarative > partition tree, and not just an inheritance tree ? I am not sure > whether it is currently possible to have a mix of these two. May be it > is easy to prevent that from happening.
It is not possible to mix declarative partitioning and regular inheritance. So, you cannot have a table in a declarative partitioning tree that is not a (sub-) partition of the root table. >>> and then run ExecFindPartition() >>> again using the root. Will check. I am not sure right now how involved >>> that would turn out to be, but I think that logic would not change the >>> existing code, so in that sense it is not invasive. >> >> I couldn't understand why run ExecFindPartition() again on the root >> partitioned table, can you clarify? ISTM, we just want to tell the user >> in the HINT that trying the same update query with root partitioned table >> might work. I'm not sure if it would work instead to find some >> intermediate partitioned table (that is, between the root and the one that >> update query was tried with) to include in the HINT. > > What I had in mind was : Give that hint only if there *was* a > subpartition that could accommodate that row. And if found, we can > only include the subpartition name. Asking to try the update query with the root table sounds like a good enough hint. Trying to find the exact sub-partition (I assume you mean to imply sub-tree here) seems like an overkill, IMHO. Thanks, Amit -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers