diff --git a/contrib/pg_walinspect/pg_walinspect.c b/contrib/pg_walinspect/pg_walinspect.c
index ee2918726d6..9e3e05e398a 100644
--- a/contrib/pg_walinspect/pg_walinspect.c
+++ b/contrib/pg_walinspect/pg_walinspect.c
@@ -101,7 +101,8 @@ InitXLogReaderState(XLogRecPtr lsn)
 	 */
 	if (lsn < XLOG_BLCKSZ)
 		ereport(ERROR,
-				(errmsg("could not read WAL at LSN %X/%X",
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("could not read WAL at LSN %X/%X",
 						LSN_FORMAT_ARGS(lsn))));
 
 	private_data = (ReadLocalXLogPageNoWaitPrivate *)
diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c
index b45b8331720..2ed3ea2b45b 100644
--- a/src/backend/access/transam/xlogrecovery.c
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -1898,7 +1898,8 @@ PerformWalRecovery(void)
 		recoveryTarget != RECOVERY_TARGET_UNSET &&
 		!reachedRecoveryTarget)
 		ereport(FATAL,
-				(errmsg("recovery ended before configured recovery target was reached")));
+				(errcode(ERRCODE_CONFIG_FILE_ERROR),
+				 errmsg("recovery ended before configured recovery target was reached")));
 }
 
 /*
diff --git a/src/backend/backup/basebackup.c b/src/backend/backup/basebackup.c
index 9a2bf59e84e..01b35e26bda 100644
--- a/src/backend/backup/basebackup.c
+++ b/src/backend/backup/basebackup.c
@@ -2045,12 +2045,14 @@ _tarWriteHeader(bbsink *sink, const char *filename, const char *linktarget,
 				break;
 			case TAR_NAME_TOO_LONG:
 				ereport(ERROR,
-						(errmsg("file name too long for tar format: \"%s\"",
+						(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+						 errmsg("file name too long for tar format: \"%s\"",
 								filename)));
 				break;
 			case TAR_SYMLINK_TOO_LONG:
 				ereport(ERROR,
-						(errmsg("symbolic link target too long for tar format: "
+						(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+						 errmsg("symbolic link target too long for tar format: "
 								"file name \"%s\", target \"%s\"",
 								filename, linktarget)));
 				break;
diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index 6d09b755564..ea05d4b224f 100644
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -803,7 +803,9 @@ refresh_by_match_merge(Oid matviewOid, Oid tempOid, Oid relowner,
 	 * That's a pretty silly thing to do.)
 	 */
 	if (!foundUniqueIndex)
-		elog(ERROR, "could not find suitable unique index on materialized view");
+		ereport(ERROR,
+				errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("could not find suitable unique index on materialized view"));
 
 	appendStringInfoString(&querybuf,
 						   " AND newdata.* OPERATOR(pg_catalog.*=) mv.*) "
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 9e9dc5c2c13..dbfe0d6b1c1 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -11363,7 +11363,8 @@ ATExecAlterConstraint(Relation rel, AlterTableCmd *cmd, bool recurse,
 		}
 
 		ereport(ERROR,
-				(errmsg("cannot alter constraint \"%s\" on relation \"%s\"",
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("cannot alter constraint \"%s\" on relation \"%s\"",
 						cmdcon->conname, RelationGetRelationName(rel)),
 				 ancestorname && ancestortable ?
 				 errdetail("Constraint \"%s\" is derived from constraint \"%s\" of relation \"%s\".",
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index 58b7fc5bbd5..170360edda8 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -1519,6 +1519,7 @@ renametrig(RenameStmt *stmt)
 		 */
 		if (OidIsValid(trigform->tgparentid))
 			ereport(ERROR,
+					errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 					errmsg("cannot rename trigger \"%s\" on table \"%s\"",
 						   stmt->subname, RelationGetRelationName(targetrel)),
 					errhint("Rename the trigger on the partitioned table \"%s\" instead.",
diff --git a/src/backend/commands/user.c b/src/backend/commands/user.c
index 104b66e4b43..e7ade898a47 100644
--- a/src/backend/commands/user.c
+++ b/src/backend/commands/user.c
@@ -1730,6 +1730,7 @@ AddRoleMems(Oid currentUserId, const char *rolename, Oid roleid,
 		 */
 		if (memberid == ROLE_PG_DATABASE_OWNER)
 			ereport(ERROR,
+					errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 					errmsg("role \"%s\" cannot be a member of any role",
 						   get_rolespec_name(memberRole)));
 
@@ -2121,6 +2122,7 @@ check_role_membership_authorization(Oid currentUserId, Oid roleid,
 	 */
 	if (is_grant && roleid == ROLE_PG_DATABASE_OWNER)
 		ereport(ERROR,
+				errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				errmsg("role \"%s\" cannot have explicit members",
 					   GetUserNameFromId(roleid, false)));
 
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 39b1a66236b..387f30cdaa8 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -250,7 +250,8 @@ be_tls_init(bool isServerStart)
 		if (ssl_ver_min > ssl_ver_max)
 		{
 			ereport(isServerStart ? FATAL : LOG,
-					(errmsg("could not set SSL protocol version range"),
+					(errcode(ERRCODE_CONFIG_FILE_ERROR),
+					 errmsg("could not set SSL protocol version range"),
 					 errdetail("\"%s\" cannot be higher than \"%s\"",
 							   "ssl_min_protocol_version",
 							   "ssl_max_protocol_version")));
diff --git a/src/backend/optimizer/util/appendinfo.c b/src/backend/optimizer/util/appendinfo.c
index 6ba4eba224a..49897226371 100644
--- a/src/backend/optimizer/util/appendinfo.c
+++ b/src/backend/optimizer/util/appendinfo.c
@@ -160,11 +160,15 @@ make_inh_translation_list(Relation oldrelation, Relation newrelation,
 
 		/* Found it, check type and collation match */
 		if (atttypid != att->atttypid || atttypmod != att->atttypmod)
-			elog(ERROR, "attribute \"%s\" of relation \"%s\" does not match parent's type",
-				 attname, RelationGetRelationName(newrelation));
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
+					 errmsg("attribute \"%s\" of relation \"%s\" does not match parent's type",
+							attname, RelationGetRelationName(newrelation))));
 		if (attcollation != att->attcollation)
-			elog(ERROR, "attribute \"%s\" of relation \"%s\" does not match parent's collation",
-				 attname, RelationGetRelationName(newrelation));
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
+					 errmsg("attribute \"%s\" of relation \"%s\" does not match parent's collation",
+							attname, RelationGetRelationName(newrelation))));
 
 		vars = lappend(vars, makeVar(newvarno,
 									 (AttrNumber) (new_attno + 1),
diff --git a/src/backend/replication/slotfuncs.c b/src/backend/replication/slotfuncs.c
index dd6c1d5a7e3..38595b3a472 100644
--- a/src/backend/replication/slotfuncs.c
+++ b/src/backend/replication/slotfuncs.c
@@ -523,7 +523,8 @@ pg_replication_slot_advance(PG_FUNCTION_ARGS)
 
 	if (XLogRecPtrIsInvalid(moveto))
 		ereport(ERROR,
-				(errmsg("invalid target WAL LSN")));
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid target WAL LSN")));
 
 	/* Build a tuple descriptor for our result type */
 	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c
index 7e5bb2b703a..2673bafe60a 100644
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -1481,7 +1481,8 @@ make_icu_collator(const char *iculocstr,
 								  UCOL_DEFAULT, UCOL_DEFAULT_STRENGTH, NULL, &status);
 		if (U_FAILURE(status))
 			ereport(ERROR,
-					(errmsg("could not open collator for locale \"%s\" with rules \"%s\": %s",
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("could not open collator for locale \"%s\" with rules \"%s\": %s",
 							iculocstr, icurules, u_errorName(status))));
 	}
 
@@ -2609,7 +2610,8 @@ pg_ucol_open(const char *loc_str)
 		if (U_FAILURE(status) || status == U_STRING_NOT_TERMINATED_WARNING)
 		{
 			ereport(ERROR,
-					(errmsg("could not get language from locale \"%s\": %s",
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("could not get language from locale \"%s\": %s",
 							loc_str, u_errorName(status))));
 		}
 
@@ -2630,7 +2632,8 @@ pg_ucol_open(const char *loc_str)
 	if (U_FAILURE(status))
 		ereport(ERROR,
 		/* use original string for error report */
-				(errmsg("could not open collator for locale \"%s\": %s",
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("could not open collator for locale \"%s\": %s",
 						orig_str, u_errorName(status))));
 
 	if (U_ICU_VERSION_MAJOR_NUM < 54)
@@ -2646,7 +2649,8 @@ pg_ucol_open(const char *loc_str)
 		{
 			ucol_close(collator);
 			ereport(ERROR,
-					(errmsg("could not open collator for locale \"%s\": %s",
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("could not open collator for locale \"%s\": %s",
 							orig_str, u_errorName(status))));
 		}
 	}
@@ -2957,7 +2961,8 @@ icu_language_tag(const char *loc_str, int elevel)
 
 		if (elevel > 0)
 			ereport(elevel,
-					(errmsg("could not convert locale name \"%s\" to language tag: %s",
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("could not convert locale name \"%s\" to language tag: %s",
 							loc_str, u_errorName(status))));
 		return NULL;
 	}
@@ -2998,7 +3003,8 @@ icu_validate_locale(const char *loc_str)
 	if (U_FAILURE(status) || status == U_STRING_NOT_TERMINATED_WARNING)
 	{
 		ereport(elevel,
-				(errmsg("could not get language from ICU locale \"%s\": %s",
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("could not get language from ICU locale \"%s\": %s",
 						loc_str, u_errorName(status)),
 				 errhint("To disable ICU locale validation, set the parameter \"%s\" to \"%s\".",
 						 "icu_validation_level", "disabled")));
@@ -3027,7 +3033,8 @@ icu_validate_locale(const char *loc_str)
 
 	if (!found)
 		ereport(elevel,
-				(errmsg("ICU locale \"%s\" has unknown language \"%s\"",
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("ICU locale \"%s\" has unknown language \"%s\"",
 						loc_str, lang),
 				 errhint("To disable ICU locale validation, set the parameter \"%s\" to \"%s\".",
 						 "icu_validation_level", "disabled")));
diff --git a/src/backend/utils/adt/tid.c b/src/backend/utils/adt/tid.c
index 8cff1e7a12e..dd46001a4eb 100644
--- a/src/backend/utils/adt/tid.c
+++ b/src/backend/utils/adt/tid.c
@@ -312,9 +312,11 @@ currtid_internal(Relation rel, ItemPointer tid)
 		return currtid_for_view(rel, tid);
 
 	if (!RELKIND_HAS_STORAGE(rel->rd_rel->relkind))
-		elog(ERROR, "cannot look at latest visible tid for relation \"%s.%s\"",
-			 get_namespace_name(RelationGetNamespace(rel)),
-			 RelationGetRelationName(rel));
+		ereport(ERROR,
+				errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("cannot look at latest visible tid for relation \"%s.%s\"",
+					   get_namespace_name(RelationGetNamespace(rel)),
+					   RelationGetRelationName(rel)));
 
 	ItemPointerCopy(tid, result);
 
@@ -349,16 +351,22 @@ currtid_for_view(Relation viewrel, ItemPointer tid)
 		if (strcmp(NameStr(attr->attname), "ctid") == 0)
 		{
 			if (attr->atttypid != TIDOID)
-				elog(ERROR, "ctid isn't of type TID");
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("ctid isn't of type TID"));
 			tididx = i;
 			break;
 		}
 	}
 	if (tididx < 0)
-		elog(ERROR, "currtid cannot handle views with no CTID");
+		ereport(ERROR,
+				errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("currtid cannot handle views with no CTID"));
 	rulelock = viewrel->rd_rules;
 	if (!rulelock)
-		elog(ERROR, "the view has no rules");
+		ereport(ERROR,
+				errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("the view has no rules"));
 	for (i = 0; i < rulelock->numLocks; i++)
 	{
 		rewrite = rulelock->rules[i];
@@ -368,7 +376,9 @@ currtid_for_view(Relation viewrel, ItemPointer tid)
 			TargetEntry *tle;
 
 			if (list_length(rewrite->actions) != 1)
-				elog(ERROR, "only one select rule is allowed in views");
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("only one select rule is allowed in views"));
 			query = (Query *) linitial(rewrite->actions);
 			tle = get_tle_by_resno(query->targetList, tididx + 1);
 			if (tle && tle->expr && IsA(tle->expr, Var))