doc: add namespace column to pg_buffercache example query

Without the namespace, the table name could be ambiguous.

Reported-by: adunham@arbormetrix.com

Discussion: https://postgr.es/m/158155175140.23798.2189464781144503491@wrigleys.postgresql.org

Backpatch-through: 9.5
This commit is contained in:
Bruce Momjian 2020-03-31 17:16:33 -04:00
parent f116356deb
commit 9e8aec433a

View File

@ -148,27 +148,28 @@
<title>Sample Output</title> <title>Sample Output</title>
<screen> <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 FROM pg_buffercache b INNER JOIN pg_class c
ON b.relfilenode = pg_relation_filenode(c.oid) AND ON b.relfilenode = pg_relation_filenode(c.oid) AND
b.reldatabase IN (0, (SELECT oid FROM pg_database b.reldatabase IN (0, (SELECT oid FROM pg_database
WHERE datname = current_database())) WHERE datname = current_database()))
GROUP BY c.relname JOIN pg_namespace n ON n.oid = c.relnamespace
ORDER BY 2 DESC GROUP BY n.nspname, c.relname
ORDER BY 3 DESC
LIMIT 10; LIMIT 10;
relname | buffers nspname | relname | buffers
---------------------------------+--------- ------------+------------------------+---------
tenk2 | 345 public | delete_test_table | 593
tenk1 | 141 public | delete_test_table_pkey | 494
pg_proc | 46 pg_catalog | pg_attribute | 472
pg_class | 45 public | quad_poly_tbl | 353
pg_attribute | 43 public | tenk2 | 349
pg_class_relname_nsp_index | 30 public | tenk1 | 349
pg_proc_proname_args_nsp_index | 28 public | gin_test_idx | 306
pg_attribute_relid_attnam_index | 26 pg_catalog | pg_largeobject | 206
pg_depend | 22 public | gin_test_tbl | 188
pg_depend_reference_index | 20 public | spgist_text_tbl | 182
(10 rows) (10 rows)
</screen> </screen>
</sect2> </sect2>