Horton

Re: [PATCH] Add pg_get_tablespace_ddl() function to reconstruct CREATE TABLESPACE statement

Chao Li <li.evan.chao@gmail.com>

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From: Chao Li <li.evan.chao@gmail.com>
To: Álvaro Herrera <alvherre@kurilemu.de>
Cc: Manni Wood <manni.wood@enterprisedb.com>, Nishant Sharma <nishant.sharma@enterprisedb.com>, Jim Jones <jim.jones@uni-muenster.de>, pgsql-hackers@postgresql.org
Date: 2025-11-13T06:06:44Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Add infrastructure for pg_get_*_ddl functions

  2. Add pg_get_tablespace_ddl() function

  3. Split out innards of pg_tablespace_location()

  4. Remove spclocation field from pg_tablespace

Hi Manni,

I just reviewed and tested the patch, just got a few small comments:

> On Nov 13, 2025, at 00:15, Álvaro Herrera <alvherre@kurilemu.de> wrote:
> 
> On 2025-Nov-12, Manni Wood wrote:
> 
>> Thanks, Álvaro, for your continued help with this.
>> 
>> I have attached v11 patches that use all of the fixes from your
>> review.patch.txt.
> 
> OK, thanks, I pushed 0001 now.
> 
> I think you could claim that some routines currently in
> src/backend/commands/tablespace.c logically belong in the new file, but
> unless you want to take on the task of moving a lot of other routines
> under commands/ to their respective catalog/ file, then I think it's
> more or less fine as is.
> 
> To be clear, I do not intend to do anything with your 0002 patch [for
> now].  I'm going to let Andrew take these DDL-producing functions in his
> hands.  Here I'm just posting your 0002 again, to make the cfbot happy.
> 
> Thanks
> 
> -- 
> Álvaro Herrera               48°01'N 7°57'E  —  https://www.EnterpriseDB.com/
> "Nunca se desea ardientemente lo que solo se desea por razón" (F. Alexandre)
> <v12-0002-Adds-pg_get_tablespace_ddl-function.patch>


1.
```
+				 errmsg("tablespace with oid %d does not exist",
```

Existing code all use “%u” to format oid. You may search for “oid %” to see that.

2.
```
+			/* Add the options in WITH clause */
+			appendStringInfoString(&buf, TextDatumGetCString(optdatums[i]));
+			appendStringInfoString(&buf, ", “);
```

This two statements can be combined into one:

appendStringInfoString(&buf,  “%s, “,  TextDatumGetCString(optdatums[i]));

3
```
+		if (strncmp(PG_TBLSPC_DIR_SLASH, path, strlen(PG_TBLSPC_DIR_SLASH)) == 0)
+			appendStringInfoString(&buf, " LOCATION ''");
+		else
+			appendStringInfo(&buf, " LOCATION '%s'", path);
+	}
```

Instead of hardcoding single-quotes, we can use quote_literal_cstr().

Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/