NDB Cluster Disk Data Tables ExtraRowAuthorBits: 0 TableStatus: Retrieved Table options: HashMap: DEFAULT-HASHMAP-3840-4 -- Attributes -- c1 Int PRIMARY KEY DISTRIBUTION KEY AT=FIXED ST=MEMORY c2 Int NULL AT=FIXED ST=MEMORY c3 Int NULL AT=FIXED ST=MEMORY c4 Int NULL AT=FIXED ST=DISK -- Indexes -- PRIMARY KEY(c1) - UniqueHashIndex i2(c3) - OrderedIndex PRIMARY(c1) - OrderedIndex i1(c2) - OrderedIndex NDBT_ProgramExit: 0 - OK Performance note.   The performance of a cluster using Disk Data storage is greatly improved if Disk Data files are kept on a separate physical disk from the data node file system. This must be done for each data node in the cluster to derive any noticeable benefit. You can use absolute and relative file system paths with  ADD UNDOFILE  and  ADD DATAFILE ; relative paths are calculated with respect to the data node’s data directory. A log file group, a tablespace, and any Disk Data tables using these must be created in a particular order. This is also true for dropping these objects, sibject to the following constraints: For example, to drop all the objects created so far in this section, you can use the following statements: These statements must be performed in the order shown, except that the two  ALTER TABLESPACE ... DROP DATAFILE  statements may be executed in either order.  The following items apply to Disk Data storage requirements: 4503 23.5.10.2 NDB Cluster Disk Data Storage Requirements •Variable-length columns of Disk Data tables take up a fixed amount of space. For each row, this is equal to the space required to store the largest possible value for that column. mysql>  DROP TABLE dt_1; mysql>  ALTER TABLESPACE ts_1 ->  DROP DATAFILE ’data_2.dat’ ->  ENGINE NDBCLUSTER; mysql>  ALTER TABLESPACE ts_1 ->  DROP DATAFILE ’data_1.dat’ ->  ENGINE NDBCLUSTER; mysql>  DROP TABLESPACE ts_1 ->  ENGINE NDBCLUSTER; mysql>  DROP LOGFILE GROUP lg_1 ->  ENGINE NDBCLUSTER; •It is not possible to drop files created in association with a different tablespace other than the one with which the files were created. •You cannot drop any data files from a tablespace as long as there remain any tables which are using the tablespace. •A tablespace cannot be dropped as long as it contains any data files. •A log file group cannot be dropped as long as any tablespaces use it.