postgres.git / summary / log / commit / refs

commit    4e7531fda587c35a4ee0fa2e5fdf90b0914a1685
Author:   Tomas Vondra <tomas.vondra@postgresql.org>
Date:     Mon Aug 19 11:31:51 2024 +0000
First released in: 18.0, 12.21, 13.17, 14.14, 15.9, 16.5, 17.0

    Explain dropdb can't use syscache because of TOAST
    
    Add a comment explaining dropdb() can't rely on syscache. The issue with
    flattened rows was fixed by commit 0f92b230f88b, but better to have
    a clear explanation why the systable scan is necessary. The other places
    doing in-place updates on pg_database have the same comment.
    
    Suggestion and patch by Yugo Nagata. Backpatch to 12, same as the fix.
    
    Author: Yugo Nagata
    Backpatch-through: 12
    Discussion: https://postgr.es/m/CAJTYsWWNkCt+-UnMhg=BiCD3Mh8c2JdHLofPxsW3m2dkDFw8RA@mail.gmail.com


 src/backend/commands/dbcommands.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index 06b7506a3d2..d3cfeb51893 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -962,7 +962,9 @@ dropdb(const char *dbname, bool missing_ok, bool force)
 	dropDatabaseDependencies(db_id);
 
 	/*
-	 * Update the database's pg_database tuple
+	 * Get the pg_database tuple to scribble on.  Note that this does not
+	 * directly rely on the syscache to avoid issues with flattened toast
+	 * values for the in-place update.
 	 */
 	ScanKeyInit(&scankey,
 				Anum_pg_database_datname,


[parent: f925b7f65d49]