Re: [HACKERS] UPDATE of partition key

On Wed, Dec 13, 2017 at 5:18 AM, Amit Khandekar <amitdkhan.pg@gmail.com> wrote:
> Amit Langote informed me off-list, - along with suggestions for
> changes - that my patch needs a rebase. Attached is the rebased
> version. I have also bumped the patch version number (now v29),
> because this as additional changes, again, suggested by Amit L :
> Because  ExecSetupPartitionTupleRouting() has mtstate parameter now,
> no need to pass update_rri and num_update_rri, since they can be
> retrieved from mtstate.
>
> Also, the preparatory patch is also rebased.

Reviewing the preparatory patch:

+ PartitionTupleRouting *partition_tuple_routing;
+ /* Tuple-routing support info */

Something's wrong with the formatting here.

-    PartitionDispatch **pd,
-    ResultRelInfo ***partitions,
-    TupleConversionMap ***tup_conv_maps,
-    TupleTableSlot **partition_tuple_slot,
-    int *num_parted, int *num_partitions)
+    PartitionTupleRouting **partition_tuple_routing)

Since we're consolidating all of ExecSetupPartitionTupleRouting's
output parameters into a single structure, I think it might make more
sense to have it just return that value.  I think it's only done with
output parameter today because there are so many different things
being produced, and we can't return them all.

+ PartitionTupleRouting *ptr = mtstate->mt_partition_tuple_routing;

This is just nitpicking, but I don't find "ptr" to be the greatest
variable name; it looks too much like "pointer".  Maybe we could use
"routing" or "proute" or something.

It seems to me that we could improve things here by adding a function
ExecCleanupTupleRouting(PartitionTupleRouting *) which would do the
various heap_close(), ExecDropSingleTupleTableSlot(), and
ExecCloseIndices() operations which are currently performed in
CopyFrom() and, by separate code, in ExecEndModifyTable().

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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