The default value for MAX_MEMORY_UNDO to 50000.

h2/src/main/org/h2/res/help.csv

@@ -999,7 +999,7 @@ SET MAX_MEMORY_ROWS 1000
 SET MAX_MEMORY_UNDO int
 ","
 The maximum number of undo records per a session that are kept in-memory.
-If a transaction is larger, the records are buffered to disk. The default value is 100000.
+If a transaction is larger, the records are buffered to disk. The default value is 50000.
 Changes to tables without a primary key can not be buffered to disk.
 This setting is persistent.
 Admin rights are required to execute this command.