Re: "debug_invalidate_system_caches_always" is too long - Mailing list pgsql-hackers

Noah Misch <noah@leadboat.com> writes:
> On Thu, Jul 08, 2021 at 04:34:55PM -0400, Tom Lane wrote:
>> Robert Haas <robertmhaas@gmail.com> writes:
>>> I like debug_discard_caches best.

>> I can live with that.  Anyone strongly against it?

> I like it.

Hearing no votes against, here's a proposed patch for that.

(This is for HEAD; I expect v14 will need additional adjustments
in release-14.sgml)

            regards, tom lane

diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out
index b8561d6a3c..e5bbf3b0af 100644
--- a/contrib/postgres_fdw/expected/postgres_fdw.out
+++ b/contrib/postgres_fdw/expected/postgres_fdw.out
@@ -9340,11 +9340,11 @@ WARNING:  there is no transaction in progress
 -- Change application_name of remote connection to special one
 -- so that we can easily terminate the connection later.
 ALTER SERVER loopback OPTIONS (application_name 'fdw_retry_check');
--- If debug_invalidate_system_caches_always is active, it results in
+-- If debug_discard_caches is active, it results in
 -- dropping remote connections after every transaction, making it
 -- impossible to test termination meaningfully.  So turn that off
 -- for this test.
-SET debug_invalidate_system_caches_always = 0;
+SET debug_discard_caches = 0;
 -- Make sure we have a remote connection.
 SELECT 1 FROM ft1 LIMIT 1;
  ?column?
@@ -9386,7 +9386,7 @@ SELECT 1 FROM ft1 LIMIT 1;    -- should fail
 ERROR:  08006
 \set VERBOSITY default
 COMMIT;
-RESET debug_invalidate_system_caches_always;
+RESET debug_discard_caches;
 -- =============================================================================
 -- test connection invalidation cases and postgres_fdw_get_connections function
 -- =============================================================================
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index c283e74715..fe503ed6c3 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -2831,11 +2831,11 @@ ROLLBACK;
 -- so that we can easily terminate the connection later.
 ALTER SERVER loopback OPTIONS (application_name 'fdw_retry_check');

--- If debug_invalidate_system_caches_always is active, it results in
+-- If debug_discard_caches is active, it results in
 -- dropping remote connections after every transaction, making it
 -- impossible to test termination meaningfully.  So turn that off
 -- for this test.
-SET debug_invalidate_system_caches_always = 0;
+SET debug_discard_caches = 0;

 -- Make sure we have a remote connection.
 SELECT 1 FROM ft1 LIMIT 1;
@@ -2861,7 +2861,7 @@ SELECT 1 FROM ft1 LIMIT 1;    -- should fail
 \set VERBOSITY default
 COMMIT;

-RESET debug_invalidate_system_caches_always;
+RESET debug_discard_caches;

 -- =============================================================================
 -- test connection invalidation cases and postgres_fdw_get_connections function
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 381d8636ab..d1b889b80f 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -10341,10 +10341,10 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
       </listitem>
      </varlistentry>

-     <varlistentry id="guc-debug-invalidate-system-caches-always" xreflabel="debug_invalidate_system_caches_always">
-      <term><varname>debug_invalidate_system_caches_always</varname> (<type>integer</type>)
+     <varlistentry id="guc-debug-discard-caches" xreflabel="debug_discard_caches">
+      <term><varname>debug_discard_caches</varname> (<type>integer</type>)
       <indexterm>
-       <primary><varname>debug_invalidate_system_caches_always</varname> configuration parameter</primary>
+       <primary><varname>debug_discard_caches</varname> configuration parameter</primary>
       </indexterm>
       </term>
       <listitem>
@@ -10369,7 +10369,7 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'

        <para>
         This parameter is supported when
-        <symbol>CLOBBER_CACHE_ENABLED</symbol> was defined at compile time
+        <symbol>DISCARD_CACHES_ENABLED</symbol> was defined at compile time
         (which happens automatically when using the
         <application>configure</application> option
         <option>--enable-cassert</option>).  In production builds, its value
diff --git a/doc/src/sgml/ref/initdb.sgml b/doc/src/sgml/ref/initdb.sgml
index 3077530c7b..e62742850a 100644
--- a/doc/src/sgml/ref/initdb.sgml
+++ b/doc/src/sgml/ref/initdb.sgml
@@ -388,17 +388,6 @@ PostgreSQL documentation
     Other, less commonly used, options are also available:

     <variablelist>
-     <varlistentry>
-      <term><option>--clobber-cache</option></term>
-      <listitem>
-       <para>
-        Run the bootstrap backend with the
-        <literal>debug_invalidate_system_caches_always=1</literal> option.
-        This takes a very long time and is only of use for deep debugging.
-       </para>
-      </listitem>
-     </varlistentry>
-
      <varlistentry>
       <term><option>-d</option></term>
       <term><option>--debug</option></term>
@@ -413,6 +402,17 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>

+     <varlistentry>
+      <term><option>--discard-caches</option></term>
+      <listitem>
+       <para>
+        Run the bootstrap backend with the
+        <literal>debug_discard_caches=1</literal> option.
+        This takes a very long time and is only of use for deep debugging.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-L <replaceable class="parameter">directory</replaceable></option></term>
       <listitem>
diff --git a/doc/src/sgml/regress.sgml b/doc/src/sgml/regress.sgml
index c35e036028..acc7a50c2f 100644
--- a/doc/src/sgml/regress.sgml
+++ b/doc/src/sgml/regress.sgml
@@ -373,7 +373,7 @@ make check EXTRA_REGRESS_OPTS="--temp-config=test_postgresql.conf"
    <para>
     This can be useful to enable additional logging, adjust resource limits,
     or enable extra run-time checks such as <xref
-    linkend="guc-debug-invalidate-system-caches-always"/>.
+    linkend="guc-debug-discard-caches"/>.
    </para>
   </sect2>

diff --git a/src/backend/utils/adt/lockfuncs.c b/src/backend/utils/adt/lockfuncs.c
index 085fec3ea2..5dc0a5882c 100644
--- a/src/backend/utils/adt/lockfuncs.c
+++ b/src/backend/utils/adt/lockfuncs.c
@@ -636,10 +636,10 @@ pg_isolation_test_session_is_blocked(PG_FUNCTION_ARGS)
      * Check if any of these are in the list of interesting PIDs, that being
      * the sessions that the isolation tester is running.  We don't use
      * "arrayoverlaps" here, because it would lead to cache lookups and one of
-     * our goals is to run quickly with debug_invalidate_system_caches_always
-     * > 0.  We expect blocking_pids to be usually empty and otherwise a very
-     * small number in isolation tester cases, so make that the outer loop of
-     * a naive search for a match.
+     * our goals is to run quickly with debug_discard_caches > 0.  We expect
+     * blocking_pids to be usually empty and otherwise a very small number in
+     * isolation tester cases, so make that the outer loop of a naive search
+     * for a match.
      */
     for (i = 0; i < num_blocking_pids; i++)
         for (j = 0; j < num_interesting_pids; j++)
diff --git a/src/backend/utils/cache/inval.c b/src/backend/utils/cache/inval.c
index d22cc5a93b..9c79775725 100644
--- a/src/backend/utils/cache/inval.c
+++ b/src/backend/utils/cache/inval.c
@@ -182,7 +182,7 @@ static int    numSharedInvalidMessagesArray;
 static int    maxSharedInvalidMessagesArray;

 /* GUC storage */
-int            debug_invalidate_system_caches_always = 0;
+int            debug_discard_caches = 0;

 /*
  * Dynamically-registered callback functions.  Current implementation
@@ -690,7 +690,7 @@ AcceptInvalidationMessages(void)
     ReceiveSharedInvalidMessages(LocalExecuteInvalidationMessage,
                                  InvalidateSystemCaches);

-    /*
+    /*----------
      * Test code to force cache flushes anytime a flush could happen.
      *
      * This helps detect intermittent faults caused by code that reads a cache
@@ -698,28 +698,28 @@ AcceptInvalidationMessages(void)
      * rarely actually does so.  This can spot issues that would otherwise
      * only arise with badly timed concurrent DDL, for example.
      *
-     * The default debug_invalidate_system_caches_always = 0 does no forced
-     * cache flushes.
+     * The default debug_discard_caches = 0 does no forced cache flushes.
      *
      * If used with CLOBBER_FREED_MEMORY,
-     * debug_invalidate_system_caches_always = 1 (CLOBBER_CACHE_ALWAYS)
+     * debug_discard_caches = 1 (formerly known as CLOBBER_CACHE_ALWAYS)
      * provides a fairly thorough test that the system contains no cache-flush
      * hazards.  However, it also makes the system unbelievably slow --- the
      * regression tests take about 100 times longer than normal.
      *
      * If you're a glutton for punishment, try
-     * debug_invalidate_system_caches_always = 3 (CLOBBER_CACHE_RECURSIVELY).
+     * debug_discard_caches = 3 (formerly known as CLOBBER_CACHE_RECURSIVELY).
      * This slows things by at least a factor of 10000, so I wouldn't suggest
      * trying to run the entire regression tests that way.  It's useful to try
      * a few simple tests, to make sure that cache reload isn't subject to
      * internal cache-flush hazards, but after you've done a few thousand
      * recursive reloads it's unlikely you'll learn more.
+     *----------
      */
-#ifdef CLOBBER_CACHE_ENABLED
+#ifdef DISCARD_CACHES_ENABLED
     {
         static int    recursion_depth = 0;

-        if (recursion_depth < debug_invalidate_system_caches_always)
+        if (recursion_depth < debug_discard_caches)
         {
             recursion_depth++;
             InvalidateSystemCaches();
diff --git a/src/backend/utils/cache/plancache.c b/src/backend/utils/cache/plancache.c
index 07b0145132..6767eae8f2 100644
--- a/src/backend/utils/cache/plancache.c
+++ b/src/backend/utils/cache/plancache.c
@@ -897,9 +897,8 @@ BuildCachedPlan(CachedPlanSource *plansource, List *qlist,
      * rejected a generic plan, it's possible to reach here with is_valid
      * false due to an invalidation while making the generic plan.  In theory
      * the invalidation must be a false positive, perhaps a consequence of an
-     * sinval reset event or the debug_invalidate_system_caches_always code.
-     * But for safety, let's treat it as real and redo the
-     * RevalidateCachedQuery call.
+     * sinval reset event or the debug_discard_caches code.  But for safety,
+     * let's treat it as real and redo the RevalidateCachedQuery call.
      */
     if (!plansource->is_valid)
         qlist = RevalidateCachedQuery(plansource, queryEnv);
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 5dac9f0696..13d9994af3 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -97,7 +97,7 @@
 #define MAYBE_RECOVER_RELATION_BUILD_MEMORY 1
 #else
 #define RECOVER_RELATION_BUILD_MEMORY 0
-#ifdef CLOBBER_CACHE_ENABLED
+#ifdef DISCARD_CACHES_ENABLED
 #define MAYBE_RECOVER_RELATION_BUILD_MEMORY 1
 #endif
 #endif
@@ -1011,10 +1011,10 @@ RelationBuildDesc(Oid targetRelId, bool insertIt)
      * data, reasoning that the caller's context is at worst of transaction
      * scope, and relcache loads shouldn't happen so often that it's essential
      * to recover transient data before end of statement/transaction.  However
-     * that's definitely not true in clobber-cache test builds, and perhaps
-     * it's not true in other cases.
+     * that's definitely not true when debug_discard_caches is active, and
+     * perhaps it's not true in other cases.
      *
-     * When cache clobbering is enabled or when forced to by
+     * When debug_discard_caches is active or when forced to by
      * RECOVER_RELATION_BUILD_MEMORY=1, arrange to allocate the junk in a
      * temporary context that we'll free before returning.  Make it a child of
      * caller's context so that it will get cleaned up appropriately if we
@@ -1024,7 +1024,7 @@ RelationBuildDesc(Oid targetRelId, bool insertIt)
     MemoryContext tmpcxt = NULL;
     MemoryContext oldcxt = NULL;

-    if (RECOVER_RELATION_BUILD_MEMORY || debug_invalidate_system_caches_always > 0)
+    if (RECOVER_RELATION_BUILD_MEMORY || debug_discard_caches > 0)
     {
         tmpcxt = AllocSetContextCreate(CurrentMemoryContext,
                                        "RelationBuildDesc workspace",
@@ -1627,11 +1627,10 @@ LookupOpclassInfo(Oid operatorClassOid,
      * otherwise.  However it can be helpful for detecting bugs in the cache
      * loading logic itself, such as reliance on a non-nailed index.  Given
      * the limited use-case and the fact that this adds a great deal of
-     * expense, we enable it only for high values of
-     * debug_invalidate_system_caches_always.
+     * expense, we enable it only for high values of debug_discard_caches.
      */
-#ifdef CLOBBER_CACHE_ENABLED
-    if (debug_invalidate_system_caches_always > 2)
+#ifdef DISCARD_CACHES_ENABLED
+    if (debug_discard_caches > 2)
         opcentry->valid = false;
 #endif

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 480e8cd199..45a053ca40 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -3513,13 +3513,13 @@ static struct config_int ConfigureNamesInt[] =
     },

     {
-        {"debug_invalidate_system_caches_always", PGC_SUSET, DEVELOPER_OPTIONS,
-            gettext_noop("Aggressively invalidate system caches for debugging purposes."),
+        {"debug_discard_caches", PGC_SUSET, DEVELOPER_OPTIONS,
+            gettext_noop("Aggressively flush system caches for debugging purposes."),
             NULL,
             GUC_NOT_IN_SAMPLE
         },
-        &debug_invalidate_system_caches_always,
-#ifdef CLOBBER_CACHE_ENABLED
+        &debug_discard_caches,
+#ifdef DISCARD_CACHES_ENABLED
         /* Set default based on older compile-time-only cache clobber macros */
 #if defined(CLOBBER_CACHE_RECURSIVELY)
         3,
@@ -3529,9 +3529,9 @@ static struct config_int ConfigureNamesInt[] =
         0,
 #endif
         0, 5,
-#else                            /* not CLOBBER_CACHE_ENABLED */
+#else                            /* not DISCARD_CACHES_ENABLED */
         0, 0, 0,
-#endif                            /* not CLOBBER_CACHE_ENABLED */
+#endif                            /* not DISCARD_CACHES_ENABLED */
         NULL, NULL, NULL
     },

diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 0945d70061..77e621a767 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -2266,8 +2266,8 @@ usage(const char *progname)
     printf(_("  -X, --waldir=WALDIR       location for the write-ahead log directory\n"));
     printf(_("      --wal-segsize=SIZE    size of WAL segments, in megabytes\n"));
     printf(_("\nLess commonly used options:\n"));
-    printf(_("      --clobber-cache       use cache-clobbering debug option\n"));
     printf(_("  -d, --debug               generate lots of debugging output\n"));
+    printf(_("      --discard-caches      set debug_discard_caches=1\n"));
     printf(_("  -L DIRECTORY              where to find the input files\n"));
     printf(_("  -n, --no-clean            do not clean up after errors\n"));
     printf(_("  -N, --no-sync             do not wait for changes to be written safely to disk\n"));
@@ -2947,7 +2947,7 @@ main(int argc, char *argv[])
         {"wal-segsize", required_argument, NULL, 12},
         {"data-checksums", no_argument, NULL, 'k'},
         {"allow-group-access", no_argument, NULL, 'g'},
-        {"clobber-cache", no_argument, NULL, 14},
+        {"discard-caches", no_argument, NULL, 14},
         {NULL, 0, NULL, 0}
     };

@@ -3092,7 +3092,7 @@ main(int argc, char *argv[])
             case 14:
                 extra_options = psprintf("%s %s",
                                          extra_options,
-                                         "-c debug_invalidate_system_caches_always=1");
+                                         "-c debug_discard_caches=1");
                 break;
             default:
                 /* getopt_long already emitted a complaint */
diff --git a/src/include/pg_config_manual.h b/src/include/pg_config_manual.h
index 27da86e5e0..614035e215 100644
--- a/src/include/pg_config_manual.h
+++ b/src/include/pg_config_manual.h
@@ -322,36 +322,36 @@
 /* #define RANDOMIZE_ALLOCATED_MEMORY */

 /*
- * For cache invalidation debugging, define CLOBBER_CACHE_ENABLED to enable
- * use of the debug_invalidate_system_caches_always GUC to aggressively flush
- * syscache/relcache entries whenever it's possible to deliver invalidations.
- * See AcceptInvalidationMessages() in src/backend/utils/cache/inval.c for
+ * For cache-invalidation debugging, define DISCARD_CACHES_ENABLED to enable
+ * use of the debug_discard_caches GUC to aggressively flush syscache/relcache
+ * entries whenever it's possible to deliver invalidations.  See
+ * AcceptInvalidationMessages() in src/backend/utils/cache/inval.c for
  * details.
  *
  * USE_ASSERT_CHECKING builds default to enabling this.  It's possible to use
- * CLOBBER_CACHE_ENABLED without a cassert build and the implied
- * CLOBBER_FREED_MEMORY and MEMORY_CONTEXT_CHECKING options but it's unlikely
+ * DISCARD_CACHES_ENABLED without a cassert build and the implied
+ * CLOBBER_FREED_MEMORY and MEMORY_CONTEXT_CHECKING options, but it's unlikely
  * to be as effective at identifying problems.
  */
-/* #define CLOBBER_CACHE_ENABLED */
+/* #define DISCARD_CACHES_ENABLED */

-#if defined(USE_ASSERT_CHECKING) && !defined(CLOBBER_CACHE_ENABLED)
-#define CLOBBER_CACHE_ENABLED
+#if defined(USE_ASSERT_CHECKING) && !defined(DISCARD_CACHES_ENABLED)
+#define DISCARD_CACHES_ENABLED
 #endif

 /*
- * Backwards compatibility for the older compile-time-only cache clobber
+ * Backwards compatibility for the older compile-time-only clobber-cache
  * macros.
  */
-#if !defined(CLOBBER_CACHE_ENABLED) && (defined(CLOBBER_CACHE_ALWAYS) || defined(CLOBBER_CACHE_RECURSIVELY))
-#define CLOBBER_CACHE_ENABLED
+#if !defined(DISCARD_CACHES_ENABLED) && (defined(CLOBBER_CACHE_ALWAYS) || defined(CLOBBER_CACHE_RECURSIVELY))
+#define DISCARD_CACHES_ENABLED
 #endif

 /*
  * Recover memory used for relcache entries when invalidated.  See
  * RelationBuildDescr() in src/backend/utils/cache/relcache.c.
  *
- * This is active automatically for clobber cache builds when clobbering is
+ * This is active automatically for clobber-cache builds when clobbering is
  * active, but can be overridden here by explicitly defining
  * RECOVER_RELATION_BUILD_MEMORY.  Define to 1 to always free relation cache
  * memory even when clobber is off, or to 0 to never free relation cache
diff --git a/src/include/utils/inval.h b/src/include/utils/inval.h
index a7e04722d0..770672890b 100644
--- a/src/include/utils/inval.h
+++ b/src/include/utils/inval.h
@@ -18,7 +18,7 @@
 #include "storage/relfilenode.h"
 #include "utils/relcache.h"

-extern PGDLLIMPORT int debug_invalidate_system_caches_always;
+extern PGDLLIMPORT int debug_discard_caches;

 typedef void (*SyscacheCallbackFunction) (Datum arg, int cacheid, uint32 hashvalue);
 typedef void (*RelcacheCallbackFunction) (Datum arg, Oid relid);
diff --git a/src/pl/plpgsql/src/expected/plpgsql_cache.out b/src/pl/plpgsql/src/expected/plpgsql_cache.out
index cc0c57b879..9df188ce56 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_cache.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_cache.out
@@ -3,10 +3,10 @@
 --
 -- These tests logically belong in plpgsql_record.sql, and perhaps someday
 -- can be merged back into it.  For now, however, their results are different
--- depending on debug_invalidate_system_caches_always, so we must have two
--- expected-output files to cover both cases.  To minimize the maintenance
--- effort resulting from that, this file should contain only tests that
--- do have different results under debug_invalidate_system_caches_always.
+-- depending on debug_discard_caches, so we must have two expected-output
+-- files to cover both cases.  To minimize the maintenance effort resulting
+-- from that, this file should contain only tests that do have different
+-- results under debug_discard_caches.
 --
 -- check behavior with changes of a named rowtype
 create table c_mutable(f1 int, f2 text);
@@ -21,7 +21,7 @@ select c_sillyaddone(42);
 alter table c_mutable drop column f1;
 alter table c_mutable add column f1 float8;
 -- currently, this fails due to cached plan for "r.f1 + 1" expression
--- (but if debug_invalidate_system_caches_always is on, it will succeed)
+-- (but if debug_discard_caches is on, it will succeed)
 select c_sillyaddone(42);
 ERROR:  type of parameter 4 (double precision) does not match that when preparing the plan (integer)
 CONTEXT:  PL/pgSQL function c_sillyaddone(integer) line 1 at RETURN
@@ -52,7 +52,7 @@ select show_result_type('select 1 as a');
 (1 row)

 -- currently this fails due to cached plan for pg_typeof expression
--- (but if debug_invalidate_system_caches_always is on, it will succeed)
+-- (but if debug_discard_caches is on, it will succeed)
 select show_result_type('select 2.0 as a');
 ERROR:  type of parameter 5 (numeric) does not match that when preparing the plan (integer)
 CONTEXT:  SQL statement "select pg_typeof(r.a)"
diff --git a/src/pl/plpgsql/src/expected/plpgsql_cache_1.out b/src/pl/plpgsql/src/expected/plpgsql_cache_1.out
index 2a42875747..3b8c73af34 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_cache_1.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_cache_1.out
@@ -3,10 +3,10 @@
 --
 -- These tests logically belong in plpgsql_record.sql, and perhaps someday
 -- can be merged back into it.  For now, however, their results are different
--- depending on debug_invalidate_system_caches_always, so we must have two
--- expected-output files to cover both cases.  To minimize the maintenance
--- effort resulting from that, this file should contain only tests that
--- do have different results under debug_invalidate_system_caches_always.
+-- depending on debug_discard_caches, so we must have two expected-output
+-- files to cover both cases.  To minimize the maintenance effort resulting
+-- from that, this file should contain only tests that do have different
+-- results under debug_discard_caches.
 --
 -- check behavior with changes of a named rowtype
 create table c_mutable(f1 int, f2 text);
@@ -21,7 +21,7 @@ select c_sillyaddone(42);
 alter table c_mutable drop column f1;
 alter table c_mutable add column f1 float8;
 -- currently, this fails due to cached plan for "r.f1 + 1" expression
--- (but if debug_invalidate_system_caches_always is on, it will succeed)
+-- (but if debug_discard_caches is on, it will succeed)
 select c_sillyaddone(42);
  c_sillyaddone
 ---------------
@@ -55,7 +55,7 @@ select show_result_type('select 1 as a');
 (1 row)

 -- currently this fails due to cached plan for pg_typeof expression
--- (but if debug_invalidate_system_caches_always is on, it will succeed)
+-- (but if debug_discard_caches is on, it will succeed)
 select show_result_type('select 2.0 as a');
     show_result_type
 ------------------------
diff --git a/src/pl/plpgsql/src/expected/plpgsql_record.out b/src/pl/plpgsql/src/expected/plpgsql_record.out
index 86d0665924..4c5d95c79e 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_record.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_record.out
@@ -426,7 +426,7 @@ select getf1(row(1,2));
      1
 (1 row)

--- the context stack is different when debug_invalidate_system_caches_always
+-- the context stack is different when debug_discard_caches
 -- is set, so suppress context output
 \set SHOW_CONTEXT never
 select getf1(row(1,2)::two_int8s);
@@ -507,7 +507,7 @@ select sillyaddone(42);
 -- test for change of type of column f1 should be here someday;
 -- for now see plpgsql_cache test
 alter table mutable drop column f1;
--- the context stack is different when debug_invalidate_system_caches_always
+-- the context stack is different when debug_discard_caches
 -- is set, so suppress context output
 \set SHOW_CONTEXT never
 select sillyaddone(42);  -- fail
@@ -527,7 +527,7 @@ select getf3(null::mutable);  -- now it works
 (1 row)

 alter table mutable drop column f3;
--- the context stack is different when debug_invalidate_system_caches_always
+-- the context stack is different when debug_discard_caches
 -- is set, so suppress context output
 \set SHOW_CONTEXT never
 select getf3(null::mutable);  -- fails again
@@ -552,7 +552,7 @@ select sillyaddtwo(42);
 (1 row)

 drop table mutable2;
--- the context stack is different when debug_invalidate_system_caches_always
+-- the context stack is different when debug_discard_caches
 -- is set, so suppress context output
 \set SHOW_CONTEXT never
 select sillyaddtwo(42);  -- fail
diff --git a/src/pl/plpgsql/src/sql/plpgsql_cache.sql b/src/pl/plpgsql/src/sql/plpgsql_cache.sql
index 061f674c9a..a48f9b2afa 100644
--- a/src/pl/plpgsql/src/sql/plpgsql_cache.sql
+++ b/src/pl/plpgsql/src/sql/plpgsql_cache.sql
@@ -3,10 +3,10 @@
 --
 -- These tests logically belong in plpgsql_record.sql, and perhaps someday
 -- can be merged back into it.  For now, however, their results are different
--- depending on debug_invalidate_system_caches_always, so we must have two
--- expected-output files to cover both cases.  To minimize the maintenance
--- effort resulting from that, this file should contain only tests that
--- do have different results under debug_invalidate_system_caches_always.
+-- depending on debug_discard_caches, so we must have two expected-output
+-- files to cover both cases.  To minimize the maintenance effort resulting
+-- from that, this file should contain only tests that do have different
+-- results under debug_discard_caches.
 --

 -- check behavior with changes of a named rowtype
@@ -20,7 +20,7 @@ alter table c_mutable drop column f1;
 alter table c_mutable add column f1 float8;

 -- currently, this fails due to cached plan for "r.f1 + 1" expression
--- (but if debug_invalidate_system_caches_always is on, it will succeed)
+-- (but if debug_discard_caches is on, it will succeed)
 select c_sillyaddone(42);

 -- but it's OK if we force plan rebuilding
@@ -42,7 +42,7 @@ $$;

 select show_result_type('select 1 as a');
 -- currently this fails due to cached plan for pg_typeof expression
--- (but if debug_invalidate_system_caches_always is on, it will succeed)
+-- (but if debug_discard_caches is on, it will succeed)
 select show_result_type('select 2.0 as a');

 -- but it's OK if we force plan rebuilding
diff --git a/src/pl/plpgsql/src/sql/plpgsql_record.sql b/src/pl/plpgsql/src/sql/plpgsql_record.sql
index 722048c730..535a3407a4 100644
--- a/src/pl/plpgsql/src/sql/plpgsql_record.sql
+++ b/src/pl/plpgsql/src/sql/plpgsql_record.sql
@@ -257,7 +257,7 @@ create function getf1(x record) returns int language plpgsql as
 $$ begin return x.f1; end $$;
 select getf1(1);
 select getf1(row(1,2));
--- the context stack is different when debug_invalidate_system_caches_always
+-- the context stack is different when debug_discard_caches
 -- is set, so suppress context output
 \set SHOW_CONTEXT never
 select getf1(row(1,2)::two_int8s);
@@ -316,7 +316,7 @@ select sillyaddone(42);
 -- for now see plpgsql_cache test

 alter table mutable drop column f1;
--- the context stack is different when debug_invalidate_system_caches_always
+-- the context stack is different when debug_discard_caches
 -- is set, so suppress context output
 \set SHOW_CONTEXT never
 select sillyaddone(42);  -- fail
@@ -328,7 +328,7 @@ select getf3(null::mutable);  -- doesn't work yet
 alter table mutable add column f3 int;
 select getf3(null::mutable);  -- now it works
 alter table mutable drop column f3;
--- the context stack is different when debug_invalidate_system_caches_always
+-- the context stack is different when debug_discard_caches
 -- is set, so suppress context output
 \set SHOW_CONTEXT never
 select getf3(null::mutable);  -- fails again
@@ -346,7 +346,7 @@ select sillyaddtwo(42);  -- fail
 create table mutable2(f1 int, f2 text);
 select sillyaddtwo(42);
 drop table mutable2;
--- the context stack is different when debug_invalidate_system_caches_always
+-- the context stack is different when debug_discard_caches
 -- is set, so suppress context output
 \set SHOW_CONTEXT never
 select sillyaddtwo(42);  -- fail
diff --git a/src/test/isolation/specs/deadlock-soft-2.spec b/src/test/isolation/specs/deadlock-soft-2.spec
index 5b7d3db503..26d9c62988 100644
--- a/src/test/isolation/specs/deadlock-soft-2.spec
+++ b/src/test/isolation/specs/deadlock-soft-2.spec
@@ -38,6 +38,6 @@ step s4c    { COMMIT; }
 # The expected output for this test assumes that isolationtester will
 # detect step s1b as waiting before the deadlock detector runs and
 # releases s1 from its blocked state.  To ensure that happens even in
-# very slow (CLOBBER_CACHE_ALWAYS) cases, apply a (*) annotation.
+# very slow (debug_discard_caches) cases, apply a (*) annotation.

 permutation s1a s2a s2b s3a s4a s1b(*) s1c s2c s3c s4c