Method, system, and program for executing a query having a union all operator and data modifying operations

• US 7,533,087 B2
• Filed: 11/05/2004
• Issued: 05/12/2009
• Est. Priority Date: 11/05/2004
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Zuzarte, Calisto Paul, Sharpe, David C., Liu, Linqi, Sutyanyong, Nattavut, Neugebauer, Robert Paul
• Primary Examiner(s): Alam; Shahid A
• Assistant Examiner(s): MYINT, DENNIS Y
• Application Number:
  US10/982,367
• Publication Number:
  US 20060101044A1
• Time in Patent Office: 1,649 Days
• Field of Search: 707/2, 707/201, 707/3, 707/4, 707/100, 707/101
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2445 Data retrieval commands; View definitions
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation

Abstract

Disclosed is a data processing system, a data processing system implemented method and an article of manufacture for executing a query having a union all operator. The data processing system implemented method directs the data processing system to execute a query against a data object. The query has a union all operator and has a set of data modifying operators. The set of data modifying operators is associated with the union all operator. The union all operator references the data object. The data processing system implemented method includes preventing the union all operator from being applied to the data object, and applying the set of data modifying operators against the data object.

Claims

1. A method of directing a data processing system to execute a query against a data object, the query having a union all operator and having a set of data modifying operators, the set of data modifying operators being associated with the union all operator, the union all operator referencing the data object, the method comprising:

determining whether a data modification operation is being requested by the query;

if no data modification operation is being requested, terminating operations of said method;

if the data modification operation is being requested, determining whether the data modification operation operates upon a data object involving one of an Updateable union all operator, Deleteable union all operator and Insertable union all operator;

if it is determined that said data modification operation does not operate upon the data object involving said one of the Updateable union all operator, Deleteable union all operator, and Insertable union all operator, terminating operations of said method;

if it is determined that the data modification operation operates upon the data object involving said one of the Updateable union all operator, Deleteable union all operator, and Insertable union all operator;

preventing the union all operator from being applied to the data object; and

applying the set of data modifying operators against the data object,

wherein the applying comprises;

analyzing every selected update operator and every selected delete operator to determine if the source for the selected update operator and the selected delete operator comes from the data objects referenced by the UNION ALL operator,

wherein the analyzing comprises;

comparing an identifier added to each source row to ensure that each data object referenced by the union all operator only contains a single identifier; and

comparing a condition in a selected data modifying operator with the identifier for all rows from particular data modifying operators referenced by the union all operator to ensure that only a single data object is the source for the selected data modifying operator.

2. The method of claim 1 wherein the set of data modifying operators comprises at least one of a delete operator, an update operator and an insert operator.

3. The method of claim 2 wherein:

the delete operator includes the target that is a deleteable UNION ALL operator;

the update operator includes the target that is an updateable UNION ALL operator; and

the insert operator includes the target that is an insertable UNION ALL operator.

4. The method of claim 1 wherein the data object includes a plurality of data objects.

5. The method of claim 1 wherein the applying comprises:

analyzing every selected update operator and every selected delete operator to determine if the source for the selected update operator and the selected delete operator comes from the data objects referenced by the UNION ALL operator.

6. The method of claim 5 wherein the analyzing comprises:

comparing an identifier added to each source row to ensure that each data object referenced by the union all operator only contains a single identifier; and

comparing a condition in a selected data modifying operator with the identifier for all rows from particular data modifying operators referenced by the union all operator to ensure that only a single data object is the source for the selected data modifying operator.

7. The method of claim 1 wherein the preventing the union all operator from being applied comprises:

determining which data object is being referred to by the union all operator; and

inserting the data modifying operator between a data operator and the union all operator.

8. An article of manufacture for directing a data processing system to execute a query against a data object, the query having a union all operator and having a set of data modifying operators, the set of data modifying operators being associated with the union all operator, the union all operator referencing the data object, the article of manufacture comprising:

a usable memory medium embodying one or more instructions executable by the data processing system, the one or more instructions comprising;

data processing system executable instructions for preventing the union all operator from being applied to the data object; and

data processing system executable instructions for applying the set of data modifying operators against the data object,

wherein a determination is made whether a data modification operation is being requested by the query;

wherein if no data modification operation is being requested, terminating operations related to executing said query against said data object,

wherein if the data modification operation is being requested, a determination is made whether the data modification operation operates upon a data object involving one of an Updateable union all operator, Deleteable union all operator and Insertable union all operator,

wherein if it is determined that said data modification operation does not operate upon the data object involving said one of the Updateable union all operator, Deleteable union all operator, and Insertable union all operator, operations related to executing said query against said data object are terminated,

wherein if it is determined that the data modification operation operates upon the data object involving said one of the Updateable union all operator, Deleteable union all operator, and Insertable union all operator;

the union all operator is prevented from being applied to the data object; and

the set of data modifying operators are applied against the data object,

wherein the applying comprises;

analyzing every selected update operator and every selected delete operator to determine if the source for the selected update operator and the selected delete operator comes from the data objects referenced by the UNION ALL operator,

wherein the analyzing comprises;

comparing an identifier added to each source row to ensure that each data object referenced by the union all operator only contains a single identifier; and

comparing a condition in a selected data modifying operator with the identifier for all rows from particular data modifying operators referenced by the union all operator to ensure that only a single data object is the source for the selected data modifying operator.

9. The article of manufacture of claim 8 wherein the set of data modifying operators comprises at least one of a delete operator, an update operator and an insert operator.

10. The article of manufacture of claim 9 wherein:

the delete operator includes a target that is the the deleteable UNION ALL operator;

the update operator includes a target that is the updateable UNION ALL operator; and

the insert operator includes a target that is the insertable UNION ALL operator.

11. The article of manufacture of claim 8 wherein the data object includes a plurality of data objects.

12. The article of manufacture of claim 8 wherein the data processing system executable instructions for applying comprises:

data processing system executable instructions for analyzing every selected update operator and every selected delete operator to determine if the source for the selected update operator and the selected delete operator comes from the data objects referenced by the UNION ALL operator.

13. The article of manufacture of claim 12 wherein the data processing system executable instructions for analyzing comprises:

data processing system executable instructions for comparing an identifier added to each source row to ensure that each data object referenced by the union all operator only contains a single identifier; and

data processing system executable instructions for comparing a condition in a selected data modifying operator with the identifier for all rows from particular data modifying operators referenced by the union all operator to ensure that only a single data object is the source for the selected data modifying operator.

14. The article of manufacture of claim 8 wherein the data processing system executable instructions for preventing the union all operator from being applied comprises:

data processing system executable instructions for determining which data operator is being referred to by the union all operator; and

data processing system executable instructions for inserting the data modifying operator between a data operator and the union all operator.