International Business Machines Corporation

Yao Ching Stephen Chen

Yun Yu Wang

Guogen Zhang

Mengchu Cai

James Willis Pickel

Fen-Ling Lin

Jeffrey William Josten

Kalpana Shyam

Li-Mey P Lee

Xiaohong Fu

Shengxi Suo

Jason Alexander Cu

Sarbinder S Kallar

Nina Bronnikova

Wei Ey Li

Robert William Lyle

Julie Ann Watts

Ruiping Li

Tammie Dang

Allan Benjamin Lebovitz

Karelle Lynne Cornwell

Yumi Kimura Tsuji

Beth Rivenes Moore

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

Sargable query-predicate evaluation for encrypted databases

Techniques are described for processing a query to produce query results, the query specifying at least a first timestamp value. Embodiments receive the query for processing and access a database index containing a plurality of database keys. The database index contains one or more database index keys, each of which includes at least a timestamp value and a time zone value. Embodiments compare the first timestamp value specified in the query with a portion of one the database index keys to locate at least a portion of the query results. More specifically, the compared portion of the database index key excludes the time zone value. The located portion of the query results is then retrieved.

Indexing timestamp with time zone value

Disclosed is a method, system, and program for processing an aggregate function. Rows that contain a reference to intermediate result structures are grouped to form groups. For each group, aggregate element structures are formed from the intermediate result structures and, if the aggregate function specifies ordering, the aggregate element structures are sorted based on a sort key.

Method, system, and program for optimizing aggregate processing

Disclosed is a method, system, and program for processing a function. A set of nested functions are received. A composite function is generated for the set of nested functions. A tagging template is generated for the set of nested functions that corresponds to the composite function. A result is produced by evaluating the composite function using the tagging template.

Method, system, and program for optimizing processing of nested functions

Provided is a method, system, and program for implementing a database trigger. Upon detecting a trigger event, a determination is made of at least one row in a base table affected by the trigger event. For each column in the base table of a data type that is referenced in a triggered action associated with the trigger event, a reference is generated referencing the data of the data type. The reference is inserted in a transition table column including data of the data type from the affected row in the base table referenced in the triggered action. The reference is used to access the data of the data type when performing the triggered action.

Method, system, and program for implementing a database trigger

Provided is a method, system, and program for processing a query including a query operation on a table derived from a set operation on two result tables. The query operation is performed on each result table separately to produce two intermediate result tables. The set operator is then applied to the two intermediate result tables to produce a final result table that is a same result table that would have been produced by performing the query operation on the table derived from the set operation performed on the two result tables.

Method, system, and program for optimizing the processing of queries involving set operators

Provided is a method, system, program, and data structures for making data available to an application program. A result table is generated including rows corresponding to a subset of rows in a base table having data in one or more columns that satisfy a query predicate clause. The result table includes, for each row, a location identifier of the corresponding row in the base table and a column for each column in a query select list. The result table is accessed to return requested data from the base table to the application program.

Method, system, and program for using a fetch request to make data available to an application program

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Saratoga, CA, United States of America

Yao Ching Stephen Chen