What is New in NDB Cluster • recover : A recovery thread retrieves data from a local checkpoint. A recovery thread specified as such never acts as a query thread. •Into a single thread by setting either one of these arguments to 0. When this is done, the resulting combined thread is shown with the name  main_rep  in the  ndbinfo.threads  table. •Together with the  recv  thread by setting both  ldm  and  tc  to 0, and setting  recv  to 1. In this case, the combined thread is named  main_rep_recv . • ndbmtd Thread Auto-Configuration.   Beginning with NDB 8.0.23, it is possible to employ automatic configuration of threads for multi-threaded data nodes using the  ndbmtd  configuration parameter AutomaticThreadConfig . When this parameter is set to 1,  NDB  sets up thread assignments automatically, based on the number of processors available to applications, for all thread supported thread types, including the new  query  and  recover  thread types described in the previous item. If Also, as the result of work done relating to this task,  NDB  now employs mutexes to protect job buffers when using more than 32 block threads. While this can cause a slight decrease in performance (1 to 2 percent in most cases), it also significantly reduces the amount of memory required by very large configurations. For example, a setup with 64 threads which used 2 GB of job buffer memory prior to NDB 8.0.23 should require only about 1 GB instead in NDB 8.0.23 and later. In our testing this has resulted in an overall improvement on the order of 5 percent in the execution of very complex queries. For more information, see the descriptions of the  ThreadConfig  parameter and the ndbinfo.threads  table. Maximums for other thread types remain unchanged. In addition, the maximum numbers of a number of existing thread types have been increased. The new maximums, including those for query threads and recovery threads, are listed here: It is also possible to combine the existing  main  and  rep  threads in either of two ways: •LDM: 332 •Query: 332 •Recovery: 332 •TC: 128 •Receive: 64 •Send: 64 •Main: 2 3954