Introduce pg_dsm_registry_allocations view.

This commit adds a new system view that provides information about
entries in the dynamic shared memory (DSM) registry.  Specifically,
it returns the name, type, and size of each entry.  Note that since
we cannot discover the size of dynamic shared memory areas (DSAs)
and hash tables backed by DSAs (dshashes) without first attaching
to them, the size column is left as NULL for those.

Bumps catversion.

Author: Florents Tselai <florents.tselai@gmail.com>
Reviewed-by: Sungwoo Chang <swchangdev@gmail.com>
Discussion: https://postgr.es/m/4D445D3E-81C5-4135-95BB-D414204A0AB4%40gmail.com

5 files changed, 47 insertions, 2 deletions

diff --git a/src/test/modules/test_dsm_registry/expected/test_dsm_registry.out b/src/test/modules/test_dsm_registry/expected/test_dsm_registry.out
index 8ded82e59d6..ca8abbb377e 100644
--- a/src/test/modules/test_dsm_registry/expected/test_dsm_registry.out
+++ b/src/test/modules/test_dsm_registry/expected/test_dsm_registry.out
@@ -1,3 +1,10 @@
+SELECT name, type, size IS DISTINCT FROM 0 AS size
+FROM pg_dsm_registry_allocations
+WHERE name like 'test_dsm_registry%' ORDER BY name;
+ name | type | size 
+------+------+------
+(0 rows)
+
 CREATE EXTENSION test_dsm_registry;
 SELECT set_val_in_shmem(1236);
  set_val_in_shmem 
@@ -24,3 +31,14 @@ SELECT get_val_in_hash('test');
  1414
 (1 row)
 
+\c
+SELECT name, type, size IS DISTINCT FROM 0 AS size
+FROM pg_dsm_registry_allocations
+WHERE name like 'test_dsm_registry%' ORDER BY name;
+          name          |  type   | size 
+------------------------+---------+------
+ test_dsm_registry_dsa  | area    | t
+ test_dsm_registry_dsm  | segment | t
+ test_dsm_registry_hash | hash    | t
+(3 rows)
+
diff --git a/src/test/modules/test_dsm_registry/sql/test_dsm_registry.sql b/src/test/modules/test_dsm_registry/sql/test_dsm_registry.sql
index c2e25cddaae..965a3f1ebb6 100644
--- a/src/test/modules/test_dsm_registry/sql/test_dsm_registry.sql
+++ b/src/test/modules/test_dsm_registry/sql/test_dsm_registry.sql
@@ -1,6 +1,13 @@
+SELECT name, type, size IS DISTINCT FROM 0 AS size
+FROM pg_dsm_registry_allocations
+WHERE name like 'test_dsm_registry%' ORDER BY name;
 CREATE EXTENSION test_dsm_registry;
 SELECT set_val_in_shmem(1236);
 SELECT set_val_in_hash('test', '1414');
 \c
 SELECT get_val_in_shmem();
 SELECT get_val_in_hash('test');
+\c
+SELECT name, type, size IS DISTINCT FROM 0 AS size
+FROM pg_dsm_registry_allocations
+WHERE name like 'test_dsm_registry%' ORDER BY name;
diff --git a/src/test/regress/expected/privileges.out b/src/test/regress/expected/privileges.out
index c25062c288f..aadc328589d 100644
--- a/src/test/regress/expected/privileges.out
+++ b/src/test/regress/expected/privileges.out
@@ -3220,7 +3220,8 @@ REVOKE MAINTAIN ON lock_table FROM regress_locktable_user;
 DROP TABLE lock_table;
 DROP USER regress_locktable_user;
 -- test to check privileges of system views pg_shmem_allocations,
--- pg_shmem_allocations_numa and pg_backend_memory_contexts.
+-- pg_shmem_allocations_numa, pg_dsm_registry_allocations, and
+-- pg_backend_memory_contexts.
 -- switch to superuser
 \c -
 CREATE ROLE regress_readallstats;
@@ -3248,6 +3249,12 @@ SELECT has_table_privilege('regress_readallstats','pg_shmem_allocations_numa','S
  f
 (1 row)
 
+SELECT has_table_privilege('regress_readallstats','pg_dsm_registry_allocations','SELECT'); -- no
+ has_table_privilege 
+---------------------
+ f
+(1 row)
+
 GRANT pg_read_all_stats TO regress_readallstats;
 SELECT has_table_privilege('regress_readallstats','pg_aios','SELECT'); -- yes
  has_table_privilege 
@@ -3273,6 +3280,12 @@ SELECT has_table_privilege('regress_readallstats','pg_shmem_allocations_numa','S
  t
 (1 row)
 
+SELECT has_table_privilege('regress_readallstats','pg_dsm_registry_allocations','SELECT'); -- yes
+ has_table_privilege 
+---------------------
+ t
+(1 row)
+
 -- run query to ensure that functions within views can be executed
 SET ROLE regress_readallstats;
 SELECT COUNT(*) >= 0 AS ok FROM pg_aios;
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 6cf828ca8d0..dce8c672b40 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1340,6 +1340,10 @@ pg_cursors| SELECT name,
     is_scrollable,
     creation_time
    FROM pg_cursor() c(name, statement, is_holdable, is_binary, is_scrollable, creation_time);
+pg_dsm_registry_allocations| SELECT name,
+    type,
+    size
+   FROM pg_get_dsm_registry_allocations() pg_get_dsm_registry_allocations(name, type, size);
 pg_file_settings| SELECT sourcefile,
     sourceline,
     seqno,
diff --git a/src/test/regress/sql/privileges.sql b/src/test/regress/sql/privileges.sql
index f337aa67c13..47bd4011dc9 100644
--- a/src/test/regress/sql/privileges.sql
+++ b/src/test/regress/sql/privileges.sql
@@ -1948,7 +1948,8 @@ DROP TABLE lock_table;
 DROP USER regress_locktable_user;
 
 -- test to check privileges of system views pg_shmem_allocations,
--- pg_shmem_allocations_numa and pg_backend_memory_contexts.
+-- pg_shmem_allocations_numa, pg_dsm_registry_allocations, and
+-- pg_backend_memory_contexts.
 
 -- switch to superuser
 \c -
@@ -1959,6 +1960,7 @@ SELECT has_table_privilege('regress_readallstats','pg_aios','SELECT'); -- no
 SELECT has_table_privilege('regress_readallstats','pg_backend_memory_contexts','SELECT'); -- no
 SELECT has_table_privilege('regress_readallstats','pg_shmem_allocations','SELECT'); -- no
 SELECT has_table_privilege('regress_readallstats','pg_shmem_allocations_numa','SELECT'); -- no
+SELECT has_table_privilege('regress_readallstats','pg_dsm_registry_allocations','SELECT'); -- no
 
 GRANT pg_read_all_stats TO regress_readallstats;
 
@@ -1966,6 +1968,7 @@ SELECT has_table_privilege('regress_readallstats','pg_aios','SELECT'); -- yes
 SELECT has_table_privilege('regress_readallstats','pg_backend_memory_contexts','SELECT'); -- yes
 SELECT has_table_privilege('regress_readallstats','pg_shmem_allocations','SELECT'); -- yes
 SELECT has_table_privilege('regress_readallstats','pg_shmem_allocations_numa','SELECT'); -- yes
+SELECT has_table_privilege('regress_readallstats','pg_dsm_registry_allocations','SELECT'); -- yes
 
 -- run query to ensure that functions within views can be executed
 SET ROLE regress_readallstats;