oin t1 using(c1);
c1 | c2 | c1 | c2
+++
(0 rows)
Table t1 and t2 both has 2 columns: c1, c2, when CTE join select *, the result
target list seems to lost one’s column c1.
But it looks good when select cte1.* and t1.* explicitly .
Is it a bug?
Regards,
Zhang Mingli
ut: t1.c1, t1.c2
-> Hash (cost=0.02..0.02 rows=1 width=8)
Output: cte1.c1, cte1.c2
-> CTE Scan on cte1 (cost=0.00..0.02 rows=1 width=8)
Output: cte1.c1, cte1.c2
(14 rows)
Regards,
Zhang Mingli
Hi
Regards,
Zhang Mingli
On Jun 28, 2023, 17:17 +0800, Julien Rouhaud , wrote:
> This is working as intended. When using a USING clause you "merge" both
> columns so the final target list only contain one version of the merged
> columns, which doesn't happen if you
uces one output column for each of the listed column pairs (in
> the listed order), followed by any remaining columns from T1, followed by any
> remaining columns from T2.
Thanks for your help.
Regards,
Zhang Mingli
also make it easy to cause
unnecessary troubles.
Shall we remove it before we provide an example for developers to avoid that?
Zhang Mingli
www.hashdata.xyz
NextFreeSlot() to avoid such issues.
[0] https://github.com/cloudberrydb/cloudberrydb
Zhang Mingli
www.hashdata.xyz
v0-0001-Fix-COPY-FROM-crash-due-to-buffer-flush.patch
Description: Binary data
Hi,
Zhang Mingli
www.hashdata.xyz
On Jul 30, 2024 at 13:35 +0800, David Rowley , wrote:
>
> If you're only able
> to get it to misbehave by setting MAX_PARTITION_BUFFERS to less than
> 2, then my suggested fix would be to add a comment to say that values
> less than to are
Hi,
Zhang Mingli
www.hashdata.xyz
On Jul 30, 2024 at 13:37 +0800, Kirill Reshke , wrote:
>
> Just to be clear, you are facing this on HEAD, on on REL_14_STABLE?
Postgres HEAD.
Hi,
Zhang Mingli
www.hashdata.xyz
On Oct 9, 2024 at 20:35 +0800, Matthias van de Meent ,
wrote:
> Hi,
>
> Whilst doing some digging in parallel code, I noticed that
> max_parallel_maintenance_workers is registered as guc with a manual
> value of 1024, while max_parallel_workers_
Hi,
Zhang Mingli
www.hashdata.xyz
On Oct 12, 2024 at 07:48 +0800, Joel Jacobson , wrote:
>
> Add missing checks for FORCE_NOT_NULL and FORCE_NULL when applied to
> all columns via "*". These options now correctly require CSV mode and
> are disallowed in COPY TO as a
Hi, all
I haven't paid attention to this topic in a long time, thanks all for the
advices, I will study them then update.
Thanks again.
Zhang Mingli
www.hashdata.xyz
On Sep 18, 2024 at 15:50 +0800, David Rowley , wrote:
> On Wed, 18 Sept 2024 at 19:28, Peter Eisentraut wrote:
&g
Hi,
Zhang Mingli
www.hashdata.xyz
On Feb 4, 2025 at 04:18 +0800, Sami Imseih , wrote:
>
> This really does not make sense as this
> optimization cannot be applied to a remote table and it
> can give a user a false impression that it was.
+1,
```
+ /*
+ * Raise an error on foreign ta
tgresql.org/docs/current/sql-alterforeigntable.html
[2] https://www.postgresql.org/docs/current/sql-createforeigntable.html
--
Zhang Mingli
HashData
I believe that
COMPRESSION should also be copied for foreign tables, similar to STORAGE.
This might be beneficial for foreign data wrappers (FDWs) that take it into
account.
[0]
https://www.postgresql.org/message-id/6cecef0e-ee14-473c-bb0a-6aa61f539a66%40Spark
--
Zhang Mingli
HashData
v
they don't
actually use storage.
Virtual columns are computed when the table is read, and they should adhere to
the same rules of join semantics.
I agree with Richard, the result seems incorrect. The right outcome should be:
gpadmin=# SELECT t2.a, t2.b FROM t t1 LEFT JOIN t t2 ON FALSE;
a | b
--+--
NULL | NULL
NULL | NULL
(2 rows)
--
Zhang Mingli
HashData
rigin of the option bits.
--
Zhang Mingli
HashData
could return NULL
actually.
gpadmin=# \pset null NULL
Null display is "NULL".
gpadmin=# select current_setting('pg_xmen', true);
current_setting
-
NULL
(1 row)
--
Zhang Mingli
HashData
W will never
> produce NULL.
Hi,
OK, LGTM.
--
Zhang Mingli
HashData
we find any, the FREEZE operation won’t be applicable. However, that's a
consideration for the future.
LGTM.
--
Zhang Mingli
HashData
On Feb 6, 2025 at 18:09 +0800, Zhang Mingli , wrote:
> On Feb 3, 2025 at 08:29 +0800, Michael Paquier , wrote:
> > On Mon, Feb 03, 2025 at 06:22:13AM +0800, Mingli Zhang wrote:
> > > Yes, I would like to provide a patch.
> > >
> > > Glad to see we have come t
On Feb 7, 2025 at 22:24 +0800, Zhang Mingli , wrote:
> On Feb 6, 2025 at 18:09 +0800, Zhang Mingli , wrote:
> > On Feb 3, 2025 at 08:29 +0800, Michael Paquier , wrote:
> > > On Mon, Feb 03, 2025 at 06:22:13AM +0800, Mingli Zhang wrote:
> > > > Yes, I
y is
> enough.
Hmm... I copied from the cases in the same file for each option.
There's no harm in having more tests, how about we keep them?
--
Zhang Mingli
HashData
v3-0001-CREATE-FOREIGN-TABLE-LIKE.patch
Description: Binary data
Zhang Mingli
www.hashdata.xyz
On Feb 1, 2025 at 20:20 +0800, Álvaro Herrera , wrote:
>
> Sure. Did you consider IMPORT FOREIGN SCHEMA?
Hi, Álvaro
Thank you very much for your suggestion.
I've looked into it, and it certainly can be beneficial, especially for
postgres_fdw.
However
E is not supported for creating
foreign tables")));
}
```
with some test cases and Documents changes.
Zhang Mingli
www.hashdata.xyz
Zhang Mingli
www.hashdata.xyz
On Jan 30, 2025 at 15:49 +0800, Matthias van de Meent
, wrote:
>
> Some time ago I noticed that every buffer table entry is quite large at 40
> bytes (+8): 16 bytes of HASHELEMENT header (of which the last 4 bytes are
> padding), 20 bytes of Buff
ve it?
Zhang Mingli
www.hashdata.xyz
execution of the REFRESH command.
Any suggestions?
Zhang Mingli
www.hashdata.xyz
Hi
Zhang Mingli
www.hashdata.xyz
On Jan 16, 2025 at 14:04 +0800, Yugo Nagata , wrote:
>
> You will be able to log the plan during the REFRESH by using auto_explain and
> setting
> log_analyze and log_nested_statements to on.
Hi Yugo,
Thank you for your help! That’s certainly a via
generation function during the rewrite stage
does not account for the Var field settings, leading to the errors we are
encountering.
--
Zhang Mingli
HashData
on the comments.
> >
> > instead of
> >
> > + Foreign tables have no real storage in PostgreSQL.
> >
> > Can it just be
> >
> > Foreign tables have no storage in PostgreSQL.
> >
> > the "real" is not needed.
Done.
Patch V2 addre
Hi,
By reading the codes in nodeAgg.c, I found that some comments are outdated.
The comments referred to the function lookup_hash_entry(), which has been
removed in commit b563594.
I've adjusted the comments to refer to the correct function to make it clear.
--
Zhang Mingli
HashData
v0
E command, tweaked a bit the part
> at the bottom where LIKE is not part of the standard.
>
> And applied.
Thanks.
--
Zhang Mingli
HashData
On Feb 18, 2025 at 09:54 +0800, Zhang Mingli , wrote:
>
> Will address the comments later, thanks for review!
Done in patch v6.
--
Zhang Mingli
HashData
v6-0001-CREATE-FOREIGN-TABLE-LIKE.patch
Description: Binary data
On Feb 10, 2025 at 16:45 +0800, Richard Guo , wrote:
> On Sun, Feb 9, 2025 at 11:15 PM Zhang Mingli wrote:
> > By reading the codes in nodeAgg.c, I found that some comments are outdated.
> > The comments referred to the function lookup_hash_entry(), which has been
> > remo
,
Good catch.
>
> Yeah, the primary key of t3 is deferred, so only the t3_c_uidx can be used.
> The test case is inconsistent with comments.
>
> It seems that the t2 does not have a unique index on z, do you forget to
> create it in the patch?
While there isn't an unique index, an unique constraint with a NOT NULL on that
column should serve the same purpose.
+alter table t2 alter column z set not null, add constraint t2_z_uidx unique
(z);
In patch v2, I made a slight adjustment: creating a unique index on t3 will
handle multiple choice scenarios.
Thanks for the patch.
--
Zhang Mingli
HashData
v2-0001-Modify-an-incorrect-regression-test-case-in-the-grou.patch
Description: Binary data
On Feb 18, 2025 at 09:54 +0800, Zhang Mingli , wrote:
>
> Will address the comments later, thanks for review!
Done in patch v6.
--
Zhang Mingli
HashData
v6-0001-CREATE-FOREIGN-TABLE-LIKE.patch
Description: Binary data
On Feb 18, 2025 at 08:49 +0800, Michael Paquier , wrote:
> On Mon, Feb 17, 2025 at 07:14:59PM +0800, Zhang Mingli wrote:
> > On Feb 17, 2025 at 15:24 +0800, Michael Paquier ,
> > wrote:
> > > + * For foreign tables, they have no storage in Postgres.
> > > + *
On Feb 28, 2025 at 02:27 +0800, David G. Johnston ,
wrote:
> On Thu, Feb 6, 2025 at 8:04 AM Zhang Mingli wrote:
> > On Feb 6, 2025 at 10:49 +0800, David G. Johnston
> > , wrote:
> > >
> > > Yes, and when it does it is doing so in lieu of an error, and thus it
rts related to
> generated, default and constraints properties. This dependency
> between both routines should be documented, I guess. Hmm.. Not sure
> where.
Comments are addressed except for this one, it might be worth considering
another patch.
--
Zhang Mingli
HashData
v5-0001-CREATE-FOREIGN-TABLE-LIKE.patch
Description: Binary data
d I think it could confuse others as well if they
encounter something like that.
> Maybe someone has a different opinion about this, and we should disallow
> setting STORAGE on an fdw table in future versions.
If that’s the case, why not today? I’d be happy to take care of it.
--
Zhang Mingli
HashData
using t_a_b_idx on t (cost=0.29..316.27 rows= width=8)
Index Cond: ((a = 1) AND (b > 1))
(3 rows)
--
Zhang Mingli
HashData
On Jul 11, 2025 at 23:57 +0800, Tom Lane , wrote:
> "David G. Johnston" writes:
> > On Friday, July 11, 2025, Zhang Mingli wrote:
> > > So, are both result sets technically correct given the absence of an ORDER
> > > BY clause?
>
> > The sys
fined.
While using a window function without ORDER BY is valid, the resulting output
seems unpredictable.
So, are both result sets technically correct given the absence of an ORDER BY
clause?
--
Zhang Mingli
HashData
allback.
May be confused if there were tables with same names under different schemas.
--
Zhang Mingli
HashData
Hi,
On Jul 11, 2025 at 10:53 +0800, Tom Lane , wrote:
> Zhang Mingli writes:
> > Do we need to rollback error_context_stack to the previous state if we
> > enter the branch for PG_CATCH()?
>
> No. The PG_TRY mechanism itself deals with that: the next outer
> leve
set_ps_display_remove_suffix();
error_context_stack = waiterrcontext.previous;
```
Do we need to rollback error_context_stack to the previous state if we enter
the branch for PG_CATCH()?
--
Zhang Mingli
HashData
ce.
For other objects related to the table, we can clearly document them.
Additionally, I have another suggestion - could we have a quick backslash
command to display DDL? Something like \d+ t1, or perhaps \dddl? Looking at the
code,
it seems there aren't many available command slots remaining.
--
Zhang Mingli
HashData
101 - 147 of 147 matches
Mail list logo
