Date: Fri, 4 Oct 2019 17:37:46 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: pgsql-hackers@lists.postgresql.org, Daniel Gustafsson <daniel@yesql.se>
Subject: Re: format of pg_upgrade loadable_libraries warning
Message-ID: <20191004213746.GD29227@momjian.us>
References: <20191002172337.GC9680@telsasoft.com>
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On Wed, Oct  2, 2019 at 12:23:37PM -0500, Justin Pryzby wrote:
> Regarding the previous thread and commit here:
> https://www.postgresql.org/message-id/flat/20180713162815.GA3835%40momjian.us
> https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=60e3bd1d7f92430b24b710ecf0559656eb8ed499
> 
> I'm suggesting to reformat the warning, which I found to be misleading:
> 
> |could not load library "$libdir/pgfincore": ERROR:  could not access file "$libdir/pgfincore": No such file or directory
> |Database: postgres
> |Database: too
> 
> To me that reads as "error message" followed by successful processing of two,
> named database, and not "error message followed by list of databases for which
> that error was experienced".  Essentially, the database names are themselves
> the "error", and the message is a prefix indicating the library version; but
> normally, error-looking things are output without a "prefix", since they
> weren't anticipated.
> 
> The existing check is optimized to check each library once, but then outputs
> each database which would try to load it.  That's an implementation detail, but
> adds to confusion, since it shows a single error-looking thing which might
> apply to multiple DBs (not obvious to me that it's associated with an DB at
> all).  That leads me to believe that after I "DROP EXTENSION" once, I can
> reasonably expect the upgrade to complete, which has a good chance of being
> wrong, and is exactly what the patch was intended to avoid :(

Understood.  This is a general problem with the way pg_upgrade displays
errors and the databases/objects associated with them.  The attached
patch fixes the output text to say "in database", e.g.:

  Could not load library "$libdir/pgfincore": ERROR:  could not access file "$libdir/pgfincore": No such file or directory
  in database: postgres
  in database: too

Would intenting help too?  I am inclined to fix this only head, and not
to backpatch the change.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +

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diff --git a/src/bin/pg_upgrade/check.c b/src/bin/pg_upgrade/check.c
new file mode 100644
index 617270f..1bbb57c
*** a/src/bin/pg_upgrade/check.c
--- b/src/bin/pg_upgrade/check.c
*************** check_for_isn_and_int8_passing_mismatch(
*** 858,864 ****
  						 output_path, strerror(errno));
  			if (!db_used)
  			{
! 				fprintf(script, "Database: %s\n", active_db->db_name);
  				db_used = true;
  			}
  			fprintf(script, "  %s.%s\n",
--- 858,864 ----
  						 output_path, strerror(errno));
  			if (!db_used)
  			{
! 				fprintf(script, "in database: %s\n", active_db->db_name);
  				db_used = true;
  			}
  			fprintf(script, "  %s.%s\n",
*************** check_for_tables_with_oids(ClusterInfo *
*** 937,943 ****
  						 output_path, strerror(errno));
  			if (!db_used)
  			{
! 				fprintf(script, "Database: %s\n", active_db->db_name);
  				db_used = true;
  			}
  			fprintf(script, "  %s.%s\n",
--- 937,943 ----
  						 output_path, strerror(errno));
  			if (!db_used)
  			{
! 				fprintf(script, "in database: %s\n", active_db->db_name);
  				db_used = true;
  			}
  			fprintf(script, "  %s.%s\n",
*************** check_for_reg_data_type_usage(ClusterInf
*** 1046,1052 ****
  						 output_path, strerror(errno));
  			if (!db_used)
  			{
! 				fprintf(script, "Database: %s\n", active_db->db_name);
  				db_used = true;
  			}
  			fprintf(script, "  %s.%s.%s\n",
--- 1046,1052 ----
  						 output_path, strerror(errno));
  			if (!db_used)
  			{
! 				fprintf(script, "in database: %s\n", active_db->db_name);
  				db_used = true;
  			}
  			fprintf(script, "  %s.%s.%s\n",
*************** check_for_jsonb_9_4_usage(ClusterInfo *c
*** 1137,1143 ****
  						 output_path, strerror(errno));
  			if (!db_used)
  			{
! 				fprintf(script, "Database: %s\n", active_db->db_name);
  				db_used = true;
  			}
  			fprintf(script, "  %s.%s.%s\n",
--- 1137,1143 ----
  						 output_path, strerror(errno));
  			if (!db_used)
  			{
! 				fprintf(script, "in database: %s\n", active_db->db_name);
  				db_used = true;
  			}
  			fprintf(script, "  %s.%s.%s\n",
diff --git a/src/bin/pg_upgrade/function.c b/src/bin/pg_upgrade/function.c
new file mode 100644
index 0c66d1c..506fd34
*** a/src/bin/pg_upgrade/function.c
--- b/src/bin/pg_upgrade/function.c
*************** check_loadable_libraries(void)
*** 256,262 ****
  		}
  
  		if (was_load_failure)
! 			fprintf(script, _("Database: %s\n"),
  					old_cluster.dbarr.dbs[os_info.libraries[libnum].dbnum].db_name);
  	}
  
--- 256,262 ----
  		}
  
  		if (was_load_failure)
! 			fprintf(script, _("in database: %s\n"),
  					old_cluster.dbarr.dbs[os_info.libraries[libnum].dbnum].db_name);
  	}
  
diff --git a/src/bin/pg_upgrade/version.c b/src/bin/pg_upgrade/version.c
new file mode 100644
index 10cb362..fba7c6c
*** a/src/bin/pg_upgrade/version.c
--- b/src/bin/pg_upgrade/version.c
*************** old_9_3_check_for_line_data_type_usage(C
*** 157,163 ****
  						 strerror(errno));
  			if (!db_used)
  			{
! 				fprintf(script, "Database: %s\n", active_db->db_name);
  				db_used = true;
  			}
  			fprintf(script, "  %s.%s.%s\n",
--- 157,163 ----
  						 strerror(errno));
  			if (!db_used)
  			{
! 				fprintf(script, "in database: %s\n", active_db->db_name);
  				db_used = true;
  			}
  			fprintf(script, "  %s.%s.%s\n",
*************** old_9_6_check_for_unknown_data_type_usag
*** 258,264 ****
  						 strerror(errno));
  			if (!db_used)
  			{
! 				fprintf(script, "Database: %s\n", active_db->db_name);
  				db_used = true;
  			}
  			fprintf(script, "  %s.%s.%s\n",
--- 258,264 ----
  						 strerror(errno));
  			if (!db_used)
  			{
! 				fprintf(script, "in database: %s\n", active_db->db_name);
  				db_used = true;
  			}
  			fprintf(script, "  %s.%s.%s\n",

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