apache / cloudberry

One advanced and mature open-source MPP (Massively Parallel Processing) database. Open source alternative to Greenplum Database.
https://cloudberry.apache.org
Apache License 2.0
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[Bug] ORCA fallbacks for collate "C" #717

Open my-ship-it opened 2 days ago

my-ship-it commented 2 days ago

Cloudberry Database version

No response

What happened

Currently, when column attribute of table is collate "C", ORCA would fallback. We need to support it in ORCA also, because sometimes ORCA would produce better plan.

What you think should happen instead

No response

How to reproduce

postgres=# create table tbl(v text);
CREATE TABLE
postgres=# create table tbl_collate_c(v text collate "C");
CREATE TABLE
postgres=# explain select * from tbl order by v;
                                  QUERY PLAN
------------------------------------------------------------------------------
 Gather Motion 3:1  (slice1; segments: 3)  (cost=0.00..431.00 rows=1 width=8)
   Merge Key: v
   ->  Sort  (cost=0.00..431.00 rows=1 width=8)
         Sort Key: v
         ->  Seq Scan on tbl  (cost=0.00..431.00 rows=1 width=8)
 Optimizer: Pivotal Optimizer (GPORCA)
(6 rows)

postgres=# explain select * from tbl_collate_c order by v;
                                      QUERY PLAN
---------------------------------------------------------------------------------------
 Gather Motion 3:1  (slice1; segments: 3)  (cost=1451.09..2199.09 rows=52800 width=32)
   Merge Key: v
   ->  Sort  (cost=1451.09..1495.09 rows=17600 width=32)
         Sort Key: v COLLATE "C"
         ->  Seq Scan on tbl_collate_c  (cost=0.00..210.00 rows=17600 width=32)
 Optimizer: Postgres query optimizer
(6 rows)

Operating System

No specific

Anything else

No response

Are you willing to submit PR?

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