Abstract: A computer-implemented method of a database statement for a relational database. The database comprises one or more tables comprising one or more data rows. A database statement is received. A set of predicates from the database statement and a set of data rows from the tables to use to generate the result of the database statement are determined. A set of interdiction statements applicable to one or more data rows is obtained. For each predicate, a set of masks applicable to one or more data rows is obtained, where for each mask, the data masked by the mask is used by the predicate. It is determined if a data row has an applicable interdiction statement, and contains data masked by a mask. If so, the result of the database statement without using the result of applying the predicate to the data row.

Abstract: As disclosed herein a computer system for secure database backup and recovery in a secure database network has N distributed data nodes. The computer system includes program instructions that include instructions to receive a database backup file, fragment the file using a fragment engine, and associate each fragment with one node, where the fragment is not stored on the associated node. The program instructions further include instructions to encrypt each fragment using a first encryption key, and store, randomly, encrypted fragments on the distributed data nodes. The program instructions further include instructions to retrieve the encrypted fragments, decrypt the encrypted fragments using the first encryption key, re-encrypt the decrypted fragments using a different encryption key, and store, randomly, the re-encrypted fragments on the distributed data nodes. A computer program product and method corresponding to the above computer system are also disclosed herein.

Abstract: In one embodiment, a method of processing a structured query language (SQL) statement is provided, comprising: determining whether a first query and a second query are equivalent, the first and second queries being respectively the left side and the right side operands of the OUTER JOIN operation; determining whether a SELECT output of the SQL statement does not refer to database columns from the left side of the OUTER JOIN operation which are not also partitioning columns of the OUTER JOIN operation; and responsive to determining that the first query and the second query are equivalent and that the SELECT output of the SQL statement does not refer to database columns from the left side of the OUTER JOIN operation which are not also partitioning columns of the OUTER JOIN operation, transforming the SQL statement into an optimized query SQL statement by removing the OUTER JOIN operation.

Abstract: In one embodiment, a method of processing a structured query language (SQL) statement is provided, comprising: determining whether a first query and a second query are equivalent, the first and second queries being respectively the left side and the right side operands of the OUTER JOIN operation; determining whether a SELECT output of the SQL statement does not refer to database columns from the left side of the OUTER JOIN operation which are not also partitioning columns of the OUTER JOIN operation; and responsive to determining that the first query and the second query are equivalent and that the SELECT output of the SQL statement does not refer to database columns from the left side of the OUTER JOIN operation which are not also partitioning columns of the OUTER JOIN operation, transforming the SQL statement into an optimized query SQL statement by removing the OUTER JOIN operation.

Abstract: As disclosed herein a computer system for secure database backup and recovery in a secure database network has N distributed data nodes. The computer system includes program instructions that include instructions to receive a database backup file, fragment the file using a fragment engine, and associate each fragment with one node, where the fragment is not stored on the associated node. The program instructions further include instructions to encrypt each fragment using a first encryption key, and store, randomly, encrypted fragments on the distributed data nodes. The program instructions further include instructions to retrieve the encrypted fragments, decrypt the encrypted fragments using the first encryption key, re-encrypt the decrypted fragments using a different encryption key, and store, randomly, the re-encrypted fragments on the distributed data nodes. A computer program product and method corresponding to the above computer system are also disclosed herein.