Re: Add SPLIT PARTITION/MERGE PARTITIONS commands

08.04.2024 01:15, Alexander Korotkov wrote:
> Thank you for spotting this. This seems like a missing check. I'm
> going to get a closer look at this tomorrow.
>

Thanks!

There is also an anomaly with the MERGE command:
CREATE TABLE t1 (i int, a int, b int, c int) PARTITION BY RANGE (a, b);
CREATE TABLE t1p1 PARTITION OF t1 FOR VALUES FROM (1, 1) TO (1, 2);

CREATE TABLE t2 (i int, t text) PARTITION BY RANGE (t);
CREATE TABLE t2pa PARTITION OF t2 FOR VALUES FROM ('A') TO ('C');

CREATE TABLE t3 (i int, t text);

ALTER TABLE t2 MERGE PARTITIONS (t1p1, t2pa, t3) INTO t2p;

leads to:
ERROR:  partition bound for relation "t3" is null
WARNING:  problem in alloc set PortalContext: detected write past chunk end in block 0x55f1ef42f820, chunk 0x55f1ef42ff40
WARNING:  problem in alloc set PortalContext: detected write past chunk end in block 0x55f1ef42f820, chunk 0x55f1ef42ff40

(I'm also not sure that the error message is clear enough (can't we say
"relation X is not a partition of relation Y" in this context, as in
MarkInheritDetached(), for example?).)

Whilst with
ALTER TABLE t2 MERGE PARTITIONS (t1p1, t2pa) INTO t2p;

I get:
Program terminated with signal SIGSEGV, Segmentation fault.

#0  pg_detoast_datum_packed (datum=0x1) at fmgr.c:1866
1866            if (VARATT_IS_COMPRESSED(datum) || VARATT_IS_EXTERNAL(datum))
(gdb) bt
#0  pg_detoast_datum_packed (datum=0x1) at fmgr.c:1866
#1  0x000055d77d00fde2 in bttextcmp (...) at ../../../../src/include/postgres.h:314
#2  0x000055d77d03fa27 in FunctionCall2Coll (...) at fmgr.c:1161
#3  0x000055d77ce1572f in partition_rbound_cmp (...) at partbounds.c:3525
#4  0x000055d77ce157b9 in qsort_partition_rbound_cmp (...) at partbounds.c:3816
#5  0x000055d77d0982ef in qsort_arg (...) at ../../src/include/lib/sort_template.h:316
#6  0x000055d77ce1d109 in calculate_partition_bound_for_merge (...) at partbounds.c:5786
#7  0x000055d77cc24b2b in transformPartitionCmdForMerge (...) at parse_utilcmd.c:3524
#8  0x000055d77cc2b555 in transformAlterTableStmt (...) at parse_utilcmd.c:3812
#9  0x000055d77ccab17c in ATParseTransformCmd (...) at tablecmds.c:5650
#10 0x000055d77ccafd09 in ATExecCmd (...) at tablecmds.c:5589
...

Best regards,
Alexander