Thread

Re: Add SPLIT PARTITION/MERGE PARTITIONS commands

Dmitry Koval <d.koval@postgrespro.ru> — 2025-09-15T22:11:19Z

Hi Alexander.

Thanks for the notes and corrections!


1) src/backend/parser/parse_utilcmd.c includes are not alphabetically 
ordered here
+#include "partitioning/partdesc.h"
+#include "partitioning/partbounds.h"

Fixed.


2) There is unicode dash in the comment of ATExecMergePartitions() here. 
  I suggest we should stick to ascii.

+   /*
+    * Check ownership of merged partitions — partitions with different
+    * owners cannot be merged. Also, collect the OIDs of these partitions
+    * during the check.
+    */

Fixed.


3) Regarding 17bcf4f545, I see btnamecmp() is collation-aware.  Should 
we also specify COLLATE "C" every time we do "ORDER BY relname"?

Queries changed.


4) This comment sounds misleading.  Probably it should say "are contained".

+/*
+ * check_parent_values_in_new_partitions
+ *
+ * (function for BY LIST partitioning)
+ *
+ * Checks that all values of split partition (with Oid partOid) 
contains in new
+ * partitions.
+ *

Changed.


5) Given what latter items say, I think the 1. should say "The DEFAULT 
partition must be at most one."

/*
  * check_partitions_for_split
  *
  * Checks new partitions for SPLIT PARTITIONS command:
  * 1. DEFAULT partition should be one.

Corrected.


6) Regarding the isolation tests.  I see we are exercising INSERTs and 
intra-partition UPDATEs.  Should we also try some cross-partition UPDATEs?

Added simple tests for cross-partition UPDATE.


7) Additionally, I've made a numerous and small fixes for grammar to the
docs directly to the patchset.

Thanks, applied.

-- 
With best regards,
Dmitry Koval

Postgres Professional: http://postgrespro.com