What is New in NDB Cluster check-missing  option with this program. To replace any missing blob parts with placeholders, use the --add-missing  option. For more information, see Section 23.4.6, “ndb_blob_tool — Check and Repair BLOB and TEXT columns of NDB Cluster Tables” . • ndbinfo versioning.  NDB 8.0.20 and later supports versioning for  ndbinfo  tables, and maintains the current definitions for its tables internally. At startup,  NDB  compares its supported  ndbinfo  version with the version stored in the data dictionary. If the versions differ,  NDB  drops any old  ndbinfo  tables and recreates them using the current definitions. • Support for Fedora Linux.   Beginning with NDB 8.0.20, Fedora Linux is a supported platform for NDB Cluster Community releases and can be installed using the RPMs supplied for this purpose by Oracle. These can be obtained from the NDB Cluster downloads page. • NDB programs—NDBT dependency removal.   The dependency of a number of  NDB  utility programs on the  NDBT  library has been removed. This library is used internally for development, and is not required for normal use; its inclusion in these programs could lead to unwanted issues when testing. • ndb_restore , in NDB 8.0.17 • ndb_delete_all , in NDB 8.0.18 • ndb_show_tables , in NDB 8.0.20 • ndb_waiter , in NDB 8.0.20 • Pushdown of outer joins and semijoins.   Work done in NDB 8.0.20 allows many outer joins and semijoins, and not only those using a primary key or unique key lookup, to be pushed down to the data nodes (see Section 8.2.1.5, “Engine Condition Pushdown Optimization” ). •There are no unpushed conditions on the table •There are no unpushed conditions on other tables in the same join nest, or in upper join nests on which it depends •All other tables in the same join nest, or in upper join nests on which it depends, are also pushed • Foreign keys and lettercasing.  NDB  stores the names of foreign keys using the case with which they were defined. Formerly, when the value of the  lower_case_table_names  system variable was set to 0, it performed case-sensitive comparisons of foreign key names as used in  SELECT  and other SQL statements with the names as stored. Beginning with NDB 8.0.20, such comparisons are now always performed in a case-insensitive fashion, regardless of the value of  lower_case_table_names . Affected programs are listed here, along with the  NDB  versions in which the dependency was removed: The principal effect of this change for users is that these programs no longer print  NDBT_ProgramExit -  status  following completion of a run. Applications that depend upon such behavior should be updated to reflect the change when upgrading to the indicated versions. Outer joins using scans which can now be pushed include those which meet the following conditions: A semijoin that uses an index scan can now be pushed if it meets the the conditions just noted for a pushed outer join, and it uses the  firstMatch  strategy (see Section 8.2.2.1, “Optimizing IN and EXISTS Subquery Predicates with Semijoin Transformations” ). When a join cannot be pushed,  EXPLAIN  should provide the reason or reasons. 3946