International Business Machines Corporation

Harold H Hall, Jr

Helga T Spickhoff

Dianne E Bergen

Doreen A Fogle

Catherine Cuong Diep

Rainer Eberhard

Hao T Chang

Jon A Youngberg

A method, system and computer program product for allocating storage for virtual machine instances. The input/output (I/O) usage of disk extents utilized by a virtual machine is saved in an I/O profile of the virtual machine. In response to deallocating the virtual machine, the I/O usage of the disk extents is extracted from its I/O profile and saved in a data structure. Upon starting a new instance of the virtual machine, new disk extents are allocated to the new virtual machine instance. The I/O usage of the disk extents for the previous incarnation of the virtual machine is applied to the disk extents allocated to the new virtual machine instance. The newly allocated disk extents can now be placed in either a solid-state drive device or a hard disk drive device based on this I/O history without requiring a twenty-four hour long cycle.

Allocating storage for virtual machine instances based on input/output (I/O) usage rate of the disk extents stored in an I/O profile of a previous incarnation of the virtual machine

The method of the invention estimates a total processing cost incident to execution of a query statement in respect of a relational database, wherein execution of the query statement results in a further execution of a trigger procedure. The method first estimates the query statement's costs by analyzing components of the query statement to determine a processing time there for in relation to a database table that is the target of the query statement. The method then determines the number of rows that are affected in the database table as a result of execution of the query statement. Next, components of a trigger procedure that is invoked in response to execution of the query statement are analyzed to determine a &ldquo;base cost&rdquo; for a single execution of the trigger procedure visa-vis data that is contained in a single row of the database table. The components of the trigger procedure are next analyzed to determine a per row cost for execution of the trigger procedure. The per row cost is determined from an estimate of time required for execution of the trigger procedure for a single row and from an estimate of time required for execution of the trigger procedure for a plurality of rows. Thereafter, the total processing cost of a query statement is calculated by adding the query statement cost to a sum of the either (i) the base cost if only one row is subjected to the query statement or (ii) the per row cost, multiplied by the number of rows affected by the query statement.

Data base optimization method for estimating query and trigger procedure costs

A computer-implemented method is provided which helps to render the differences between relational database management system (RDBMS) types transparent. The computerized process enables database objects and authorizations on objects, as well as user privileges, to be moved or copied from one RDBMS to another within a distributed relational database environment without requiring a database administrator to have expertise in every RDBMS type in that environment. The computerized process is achieved using three inter-related and inter-dependent tables, a translation table, an implications table and a composition table which are stored in a computer memory and accessed through a computer. These tables provide a mapping matrix between database objects of a plurality of RDBMSs.

Computer program product for rendering relational database management

System for copying from one database management system to another by

Growing community of inventors

San Jose, CA, United States of America

Harold H Hall, Jr