Adaptive relational database access

• US 9,659,036 B2
• Filed: 08/31/2012
• Issued: 05/23/2017
• Est. Priority Date: 03/29/2010
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Catterall, Roy Antony, Chandler, Allan Thomas, Place, Alan David, Shewell, Mark Andrew, Yates, Stephen James
• Primary Examiner(s): Bullock, Joshua
• Application Number:
  US13/600,584
• Publication Number:
  US 20120323845A1
• Time in Patent Office: 1,726 Days
• Field of Search: 707803, 707802, 707705
• CPC Class Codes: G06F 16/20 of structured data, e.g. relational data
• CPC Class Codes: G06F 16/213 with details for schema evolution support

Abstract

An approach is provided that receives an alteration request to mark a selected column in a database table as an unused column. A database control table is then updated to indicate that the selected column is unused. After the database control table is updated, when a read request is received for the selected column, the same data is returned for the selected column for each row being read and this data is not stored in the database table.

Claims

1. A machine-implemented method comprising:

receiving a first alteration request to mark a selected column in a database table as an unused column, wherein the first alteration request includes a write value;

updating a database control table indicating that the selected column is unused and storing the write value in the database control table;

receiving a write request corresponding to the selected column, wherein the write request includes write data and identifies one or more rows to write in the database table;

in response to the selected column existing in the database table, writing the previously stored write value to the selected column of the one or more rows, wherein the write data included in the write request is not written to the selected column of the one or more rows;

in response to the selected column not existing in the database table, inhibiting writing of any data to the selected column of the one or more rows;

in response to receiving a second alteration request to mark the selected column in the database table as a used column;

updating the database control table indicating that that the selected column is used;

in response to receiving a read request to read a first set of one or more rows, retrieving a data stored in the selected column from the database table at the first set of rows; and

in response to receiving a second write request to write a provided data to a second set of one or more rows, writing the provided data to the selected column in the database table at the second set of rows.

2. The method of claim 1 further comprising:

determining that the selected column is unused by checking the database control table.

3. An information handling system comprising:

one or more processors;

a memory accessible by at least one of the processors;

a nonvolatile storage medium accessible by at least one of the processors;

a database management system including a set of instructions stored in the memory and executed by at least one of the processors in order to perform actions of;

receiving a first alteration request to mark a selected column in a database table as an unused column, wherein the first alteration request includes a write value;

updating a database control table indicating that the selected column is unused and storing the write value in the database control table;

receiving a write request corresponding to the selected column, wherein the write request includes write data and identifies one or more rows to write in the database table;

in response to the selected column existing in the database table, writing the previously stored write value to the selected column of the one or more rows, wherein the write data included in the write request is not written to the selected column of the one or more rows;

in response to the selected column not existing in the database table, inhibiting writing of any data to the selected column of the one or more rows;

in response to receiving a second alteration request to mark the selected column in the database table as a used column;

updating the database control table indicating that that the selected column is used;

in response to receiving a read request to read a first set of one or more rows, retrieving a data stored in the selected column from the database table at the first set of rows; and

in response to receiving a second write request to write a provided data to a second set of one or more rows, writing the provided data to the selected column in the database table at the second set of rows.

4. The information handling system of claim 3 wherein the actions further comprise:

determining that the selected column is unused by checking the database control table.

5. A computer program product comprising:

a non-transitory computer readable storage medium;

first program instructions to receive a first alteration request to mark a selected column in a database table as an unused column, wherein the first alteration request includes a write value;

second program instructions to update a database control table indicating that the selected column is unused and to store the write value in the database control table;

third program instructions to receive a write request corresponding to the selected column, wherein the write request includes write data and identifies one or more rows to write in the database table;

fourth program instructions to write the previously stored write value to the selected column of the one or more rows, wherein the write data included in the write request is not written to the selected column of the one or more rows, in response to the selected column existing in the database table;

fifth program instructions to inhibit writing of any data to the selected column of the one or more rows in response to the selected column not existing in the database table;

sixth program instructions to receive a second alteration request to mark the selected column in the database table as a used column;

seventh program instructions to update the database control table indicating that the selected column is used;

after the database control table is updated to indicate that the selected column is used;

eighth program instructions to receive a read request to read a first set of one or more rows;

ninth program instructions to retrieve a data stored in the selected column from the database table at the first set of rows;

tenth program instructions to receive a subsequent write request to write a provided data to a second set of one or more rows;

eleventh program instructions to write the provided data to the selected column in the database table at the second set of rows; and

wherein the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh program instructions are stored on the non-transitory computer readable storage medium.

6. The computer program product of claim 5 further comprising:

twelfth program instructions to determine that the selected column is unused by checking the database control table; and

wherein the twelfth program instructions are stored on the non-transitory computer readable storage medium.