International Business Machines Corporation

Shengxi Suo

Terence Patrick Purcell

Thomas Abel Beavin

Jae Hwang Lee

James Willis Pickel

Oliver Draese

Jeffrey William Josten

Mengchu Cai

Andrei Fedorovich Lurie

Shuanglin Guo

Xiaohong Fu

Yao Ching Stephen Chen

Li-Mey P Lee

Brian L Baggett

Dengfeng Gao

Nina Bronnikova

Sarbinder S Kallar

Fen-Ling Lin

Tammie Dang

John Joseph Campbell

Claire Willey McFeely

Euna Park

Thomas Eng

Aspects of the invention include techniques for providing a schema evolution on a live database system without an outage. A non-limiting example method includes initiating a schema change on a live database system. The schema change includes an attribute for a database object. A first application package having a user application that is dependent on the database object and that is bound with a release(deallocate) option is identified. Existing threads and new threads executing the first application package are routed to execute the first application package with a release(commit) option and the schema change on the live database system is completed. One or more additional threads concurrently executing one or more additional application packages remain executing with the release(deallocate) option.

Schema evolution on a live database system without an outage

A database-management system provides sargable evaluation for query predicates that compare an 'LHS' encrypted database-column operand to an 'RHS' expression operand. The system directly compares the two operands if all their attributes match. If the operands are encrypted string-type values differing only in length, the system truncates the RHS or pads it with encrypted blanks and, if a truncation loses meaningful data, evaluates the predicate as never satisfying an equality condition. In all other cases, if all attributes of a plaintext RHS don't match those of the plaintext data encoded into the LHS column, the system attempts to cast the RHS to match the plaintext LHS data. An error condition or data loss at this step allows the system to sargably evaluate the predicate without further analysis, but if the casting is successful and error-free, the system encrypts the resulting RHS and performs a sargable predicate evaluation.

Sargable evaluation of queries submitted to an encrypted database

A method, system and computer program product are provided. A first index scan of records of a database table is performed. A first index used by the first index scan is specified in a DBMS query statement as being ordered by one or more field values of one or more fields of the first index. A second scan of the database table is performed to determine whether each respective record of the second scan is qualified based on one or more fields of the each respective record of the second scan and a predicate. A lookup data structure is built indicating whether each of the respective records of the second scan is qualified. The lookup data structure is used to determine whether a record of the first index scan is qualified when the lookup data structure becomes available.

Helper scan in a database management system

Sargable query-predicate evaluation for encrypted databases

System, method, and computer program product to modify a received query, the received query including a first predicate specifying a comparison operator and a second predicate specifying an IS NULL operator, by replacing the comparison operator of the first predicate with an extended comparison operator, and removing the IS NULL operator from the received query, the extended comparison operator configured to support searching of NULL values in a database management system (DBMS), wherein the extended comparison operator is configured to return rows having column data matching a value predefined to represent NULL values.

Boolean term conversion for null-tolerant disjunctive predicates

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San Jose, CA, United States of America

Shengxi Suo