International Business Machines Corporation

Headway Technologies, Incorporated

Charles H Lin

Jay A Yothers

Kochan Ju

Mao-Min Chen

Cherng-Chyi Han

Julie Ann Watts

Kalpana Shyam

Jerry Mukai

Craig Alan Friske

You Feng Zheng

Regina J Liu

Binghui Zhong

Cherri M Vidmar

Curt Lee Cotner

James Willis Pickel

Tammie Dang

Claire Willey McFeely

Brian Keith Howell

Fung Lee

Hui-An Lee

Jennifer W Ou

Dropping of columns from a table with data availability, where the columns in the table are each associated with a column number, includes: executing a statement to drop a given column in the table and deferring an application of the statement until a reorganization of a current data set including the table. When the reorganization of the current data set is performed, the reorganization includes: updating column numbers for columns in each row of the table using a mapping data structure to remove the given column; loading the plurality of data rows with the updated column numbers into a shadow data set; applying to the shadow data set any changes to the table that are concurrent with the reorganization; updating a schema definition of the table with the updated column numbers; and switching the current data set to the shadow data set.

Dropping columns from a table with minimized unavailability

A method and system for providing package resolution in a database system is disclosed. The method and system comprise providing a statement within a server which allows an application to identify a list of package collections. The method and system further includes executing the statement to obtain the appropriate package. A system and method in accordance with the present invention provides a new current package path value, which is set via a statement referred to as Set Current Package Path. The SET CURRENT PACKAGE PATH statement allows the application to supply a precedence list of qualified package collections during execution time, therefore the scheme for resolving packages can be changed at any point during execution. The SET CURRENT PACKAGE PATH statement improves application development by making the package resolution mechanism less error prone and less tedious for the application developer, while providing an optimal-performance solution in the client-server environment.

Package resolution mechanism for database systems

A magnetic read head with reduced side reading characteristics is described. This design combines use of a current channeling layer (CCL) with stabilizing longitudinal bias layers whose magnetization direction is canted relative to that of the free layer easy axis and that of the pinned layer (of the GMR). This provides several advantages: First, the canting of the free layer at the side region results in a reduction of side reading by reducing magnetic sensitivity in that region. Second, the CCL leads to a narrow current flow profile at the side region, therefore producing a narrow track width definition. A process for making this device is described. Said process allows some of the requirements for interface cleaning associated with prior art processes to be relaxed.

Biased spin valve head with canted adjacent layer and current channeling layer

An improved read-write head for use with magnetic disks is described. This improvement has been achieved by providing the read head with shields that are limited to performing only shielding and do not share other magnetic functions with parts of the write head. This allows the write pole to be located very close to the read head since the top shield is no longer required to provide a flux return path, this function now being provided by a separate return flux pole. The separation between the read and write heads is now limited only by the need to achieve an optimum vertical field profile. Two key advantages of this structure are a substantial reduction in the jagging distance of the system and a reduced interference field from the write flux.

Inverted write head for vertical recording

Process of manufacturing a magnetic read head

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San Jose, CA, United States of America

Charles H Lin