Hello. While reading the docs for the enable_partitionwise_aggregate
parameter on the Query Planning page, I thought the description had a small
mistake that could be improved.
The current wording is: "which allows grouping or aggregation on a
partitioned tables performed separately "
Page: https://www.postgresql.org/docs/current/runtime-config-query.html
I think possible better alternatives could be:
- (Option 1) a "partitioned table's partitions" (the possessive form of
"it's"). The "enable_partition_pruning" parameter uses "the partitioned
table's partitions" in this form. I think this option is good, but I had a
slight preference for option 2.
- (Option 2) Or to just cut out the first part and say "to be performed
separately for each partition", which seemed simpler. So the sentence
reads: "which allows grouping or aggregation to be performed separately for
each partition"
- (Option 3) dropping the "a" so it says "which allows grouping or
aggregation on partitioned tables performed separately". I don't think this
is as good though because the aggregation happens on the partitions, so it
feels slightly off to me to say the "partitioned tables" instead of the
partitions.
I tested toggling this parameter on and off with a test partitioned table,
and looked at the query execution plan, and saw how the aggregation
happened on the partitions first when it was enabled.
This is my first ever submission to pgsql-hackers. :) I used this guide
from Lætitia to prepare the patch file for Option 2 above, which is
attached. I am having a problem with the "make STYLE=website html" step, so
I hadn't seen the preview (still fixing this up).
https://mydbanotebook.org/post/patching-doc/
Let me know what you think!
Thanks.
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 924309af26..167248a5da 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -5271,9 +5271,8 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
<listitem>
<para>
Enables or disables the query planner's use of partitionwise grouping
- or aggregation, which allows grouping or aggregation on a partitioned
- tables performed separately for each partition. If the <literal>GROUP
- BY</literal> clause does not include the partition keys, only partial
+ or aggregation, which allows grouping or aggregation to be performed separately for each
+ partition. If the <literal>GROUP BY</literal> clause does not include the partition keys, only partial
aggregation can be performed on a per-partition basis, and
finalization must be performed later. Because partitionwise grouping
or aggregation can use significantly more CPU time and memory during
