Setting UpdateOverwriteMode (integer) renamed to AllowUpdateOverwrite (boolean).

Author: hvlad

builds/install/misc/firebird.conf

@@ -524,15 +524,18 @@
 
 
 # ----------------------------
-# Defines how UPDATE should handle the case when a record was updated by trigger.
+# Defines how UPDATE should handle the case when a record was already updated by 
+# trigger or by the another positional UPDATE in the same cursor.
 #
 # It is possible that BEFORE or AFTER UPDATE trigger was fired previously by the
 # current UPDATE statement for the other record and has already changed the
 # current record being updated. Due to cursor stability, UPDATE should not see
 # such changes, and could silently overwrite them.
 #
-# If set to 0 (default), trigger changes will be overwritten by the	UPDATE.
-# If set to 1, error "UPDATE will overwrite changes made by trigger" will be raised.
+# Setting AllowUpdateOverwrite manage how engine should handle such cases:
+# - if set to true (default), prior changes will be overwritten,
+# - if set to false, error "UPDATE will overwrite changes made by the trigger or 
+#	by the another UPDATE in the same cursor" will be raised.
 #
 # CAUTION!
 # There is no guarantee that this setting will be available in future Firebird
@@ -542,7 +545,8 @@
 #
 # Type: integer
 #
-#UpdateOverwriteMode = 0
+#AllowUpdateOverwrite = true
+
 
 # ============================
 # Plugin settings

src/common/config/config.cpp

@@ -434,9 +434,6 @@ void Config::checkValues()
 
 	checkIntForLoBound(KEY_PARALLEL_WORKERS, 1, true);
 	checkIntForHiBound(KEY_PARALLEL_WORKERS, values[KEY_MAX_PARALLEL_WORKERS].intVal, false);
-
-	checkIntForLoBound(KEY_UPDATE_OVERWRITE_MODE, 0, true);
-	checkIntForHiBound(KEY_UPDATE_OVERWRITE_MODE, 1, false);
 }
 
 

src/common/config/config.h

@@ -194,7 +194,7 @@ enum ConfigKey
 	KEY_OPTIMIZE_FOR_FIRST_ROWS,
 	KEY_OUTER_JOIN_CONVERSION,
 	KEY_SUBQUERY_CONVERSION,
-	KEY_UPDATE_OVERWRITE_MODE,
+	KEY_ALLOW_UPDATE_OVERWRITE,
 	MAX_CONFIG_KEY		// keep it last
 };
 
@@ -316,7 +316,7 @@ constexpr ConfigEntry entries[MAX_CONFIG_KEY] =
 	{TYPE_BOOLEAN,	"OptimizeForFirstRows",		false,	false},
 	{TYPE_BOOLEAN,	"OuterJoinConversion",		false,	true},
 	{TYPE_BOOLEAN,	"SubQueryConversion",		false,	false},
-	{TYPE_INTEGER,	"UpdateOverwriteMode",		false,	0}
+	{TYPE_BOOLEAN,	"AllowUpdateOverwrite",		false,	true}
 };
 
 
@@ -655,7 +655,7 @@ class Config : public RefCounted, public GlobalStorage
 
 	CONFIG_GET_PER_DB_BOOL(getSubQueryConversion, KEY_SUBQUERY_CONVERSION);
 
-	CONFIG_GET_PER_DB_INT(getUpdateOverwriteMode, KEY_UPDATE_OVERWRITE_MODE);
+	CONFIG_GET_PER_DB_BOOL(getAllowUpdateOverwrite, KEY_ALLOW_UPDATE_OVERWRITE);
 };
 
 // Implementation of interface to access master configuration file

src/include/firebird/impl/msg/jrd.h

@@ -976,4 +976,4 @@ FB_IMPL_MSG(JRD, 991, sweep_attach_no_cleanup, -901, "42", "000", "Attachment ha
 // Codes 992..997 are used in v6
 FB_IMPL_MSG(JRD, 998, no_user_att_while_restore, -901, "HY", "000", "User attachments are not allowed for the database being restored")
 // Codes 999..1004 are used in v6
-FB_IMPL_MSG(JRD, 1005, update_overwrite_trigger, -901, "27", "000", "UPDATE will overwrite changes made by trigger")
+FB_IMPL_MSG(JRD, 1005, update_overwrite, -901, "27", "000", "UPDATE will overwrite changes made by the trigger or by the another UPDATE in the same cursor")

src/jrd/vio.cpp

@@ -6617,16 +6617,16 @@ static void refresh_changed_fields(thread_db* tdbb, Record* old_rec, record_para
  * Functional description
  *	Update new_rpb with foreign key fields values changed by cascade triggers.
  *  Consider self-referenced foreign keys only.
- *  Also, if UpdateOverwriteMode is set to 1, raise error when non self-referenced
- *  foreign key fields were changed by user triggers.
+ *  Also, if AllowUpdateOverwrite is set to false, raise error when non
+ *  self-referenced foreign key fields were changed by user triggers.
  *
  *  old_rec - old record before modify
  *  cur_rpb - just read record with possibly changed fields
  *  new_rpb - new record evaluated by modify statement and before-triggers
  *
  **************************************/
 	const Database* dbb = tdbb->getDatabase();
-	const auto overwriteMode = dbb->dbb_config->getUpdateOverwriteMode();
+	const auto allowOverwrite = dbb->dbb_config->getAllowUpdateOverwrite();
 
 	jrd_rel* relation = cur_rpb->rpb_relation;
 
@@ -6664,16 +6664,15 @@ static void refresh_changed_fields(thread_db* tdbb, Record* old_rec, record_para
 
 	if (fields.isEmpty())
 	{
-		if (overwriteMode == 0)
+		if (allowOverwrite)
 			return;
 
 		if (cur_rpb->rpb_record->getFormat()->fmt_version == old_rec->getFormat()->fmt_version)
 		{
 			if (memcmp(cur_rpb->rpb_address, old_rec->getData(), cur_rpb->rpb_length) == 0)
 				return;
 
-			fb_assert(overwriteMode == 1);
-			ERR_post(Arg::Gds(isc_update_overwrite_trigger));		// UPDATE will overwrite changes made by trigger
+			ERR_post(Arg::Gds(isc_update_overwrite));		// UPDATE will overwrite changes made by the trigger or by another UPDATE in the same cursor
 		}
 		// Else compare field-by-field
 	}
@@ -6686,7 +6685,7 @@ static void refresh_changed_fields(thread_db* tdbb, Record* old_rec, record_para
 		const bool is_fk = (frn < fields.getCount() && fields[frn] == fld);
 		if (!is_fk)
 		{
-			if (overwriteMode == 0)
+			if (allowOverwrite)
 				continue;
 
 			dsc dsc_cur;
@@ -6697,8 +6696,7 @@ static void refresh_changed_fields(thread_db* tdbb, Record* old_rec, record_para
 				(flag_cur && flag_old && MOV_compare(tdbb, &dsc_old, &dsc_cur) != 0))
 			{
 				// Record was modified by trigger.
-				fb_assert(overwriteMode == 1);
-				ERR_post(Arg::Gds(isc_update_overwrite_trigger));	// UPDATE will overwrite changes made by trigger
+				ERR_post(Arg::Gds(isc_update_overwrite));		// UPDATE will overwrite changes made by the trigger or by another UPDATE in the same cursor
 			}
 		}
 		else