On 2020-03-31 23:16, Bruce Momjian wrote:
doc: add namespace column to pg_buffercache example query
Without the namespace, the table name could be ambiguous.
Reported-by: [email protected]
Discussion:
https://postgr.es/m/[email protected]
Backpatch-through: 9.5
<screen>
-regression=# SELECT c.relname, count(*) AS buffers
+regression=# SELECT n.nspname, c.relname, count(*) AS buffers
FROM pg_buffercache b INNER JOIN pg_class c
ON b.relfilenode = pg_relation_filenode(c.oid) AND
b.reldatabase IN (0, (SELECT oid FROM pg_database
WHERE datname = current_database()))
- GROUP BY c.relname
- ORDER BY 2 DESC
+ JOIN pg_namespace n ON n.oid = c.relnamespace
+ GROUP BY n.nspname, c.relname
+ ORDER BY 3 DESC
LIMIT 10;
Seems kind of confusing to use INNER JOIN once and then JOIN the other time.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
