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: Manni Wood <manni.wood@enterprisedb.com>
Cc: Álvaro Herrera <alvherre@kurilemu.de>, Nishant Sharma <nishant.sharma@enterprisedb.com>, Jim Jones <jim.jones@uni-muenster.de>, pgsql-hackers@postgresql.org
Date: 2025-11-19T03:13:00Z
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 v13 again, and still got a couple of comments:

> On Nov 18, 2025, at 22:15, Manni Wood <manni.wood@enterprisedb.com> wrote:
> 
> 
> <v13-0001-Adds-pg_get_tablespace_ddl-function.patch>

1. Do we need to perform some privilege check? I just did a test:
```
evantest=> \c
You are now connected to database "evantest" as user "evan".
evantest=> select pg_get_tablespace_ddl('pg_default');
           pg_get_tablespace_ddl
-------------------------------------------
 CREATE TABLESPACE pg_default OWNER chaol;
(1 row)
```

Where “evan” is a new user without grant any persuasion to it, but it can view the system default tablespace’s DDL. I don’t think that’s expected.

2. 
```
+		optarray = DatumGetArrayTypeP(datum);
+
+		deconstruct_array_builtin(optarray, TEXTOID,
+								  &optdatums, NULL, &optcount);
+
+		Assert(optcount);
+
+		/* Start WITH clause */
+		appendStringInfoString(&buf, " WITH (");
+
+		for (i = 0; i < (optcount - 1); i++)	/* Skipping last option */
+		{
+			/* Add the options in WITH clause */
+			appendStringInfo(&buf, "%s, ", TextDatumGetCString(optdatums[i]));
+		}
+
+		/* Adding the last remaining option */
+		appendStringInfoString(&buf, TextDatumGetCString(optdatums[i]));
```

This block of code is a duplicate of get_reloptions() defined in ruleutils.c, and get_reloptions() performs more checks. So I think build_tablespace_ddl_string() should be defined in ruleutils.c and reuse the existing helper function.

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