castor

Refactor OQL query engine during GSoC 2008

Details

  • Type: Improvement Improvement
  • Status: Closed Closed
  • Priority: Major Major
  • Resolution: Fixed
  • Affects Version/s: 1.2, 1.3, 1.3.1
  • Fix Version/s: 1.3.2
  • Component/s: JDO queries
  • Labels:
    None
  • Number of attachments :
    2

Description

During GSoC 2008 Udai Gupta will work at refactoring OQL query engine. The original project idea is:

The object query language that Castor supports today is quite limited and has to be improved in some ways. On the other hand this task is very difficult as the codebase of the query engine is a bit crapy and split over many classes in different packages. To overcome this situation we plan to approach the problem from 2 sides. One is to refactor the generation of SQL queries at the current codebase. We think that this should make it much easier to replace the OQL to SQL transformation and plugin a new object query language later on. The implementation of the new OQL from scratch is the other side to approach a solution.

For the new object query language we like to conform to EJB QL specified at persistence part of EJB 3.0 specification. The specification can be downlaoded from http://jcp.org/aboutJava/communityprocess/final/jsr220/index.html.

As it will be quite difficult to implement the whole language at once, the first task will be to define a roadmap for the implementation. The roadmap should contain a list of features as well as the BNF for each step of the implementation. Based on this roadmap we intend to define your targets for the project together with you.

The base idea for the implementation is the create a class for every element of the language. This will enable us to represent a query with a hierarchy of objects of these classes. By calling toString() at the root of the hierarchy a string representation of the query can be generated. For the opposit direction, to transfor a query string into a class hierarchy, you generate a parser using a parser generator like JavaCC or antlr. Apart of the featurs you have to implement junit tests to verify that your implementation works as expected.

To limit the scope of this project, we do not expect you to implement the full specification nor to integrate the new object query language into Castor. This will be done later on at a follow up project. We only expect you to implement the query string to object transformation and vice versa for a subset of the language.

  1. Text File
    query-engine.txt
    02/Sep/08 5:59 PM
    794 kB
    Ralf Joachim
  2. GZip Archive
    Udai_Gupta.tar.gz
    03/Sep/08 2:24 AM
    4.33 MB
    Udai Gupta

Issue Links

is related to

Improvement - An improvement or enhancement to an existing feature or task. CASTOR-2616 Refactor query objects created during GSoC 2008 to comply with JPA 2.0 criteria API

  • Major - Major loss of function.
  • Closed - The issue is considered finished, the resolution is correct. Issues which are not closed can be reopened.
relates to

Sub-task - The sub-task of the issue CASTOR-2377 Refactor old tests TC30 and TC31

  • Minor - Minor loss of function, or other problem where easy workaround is present.
  • Closed - The issue is considered finished, the resolution is correct. Issues which are not closed can be reopened.

Sub-task - The sub-task of the issue CASTOR-2796 Add query objects as created at GSoC 2008 to SVN trunc

  • Trivial - Cosmetic problem like misspelt words or misaligned text.
  • Closed - The issue is considered finished, the resolution is correct. Issues which are not closed can be reopened.

Improvement - An improvement or enhancement to an existing feature or task. CASTOR-324 Castor's OQL implementation should be refactored to make use of ANTLR

  • Major - Major loss of function.
  • Open - The issue is open and ready for the assignee to start work on it.

Improvement - An improvement or enhancement to an existing feature or task. CASTOR-2368 Creating a How To for setting the castor project in Eclipse

  • Trivial - Cosmetic problem like misspelt words or misaligned text.
  • Closed - The issue is considered finished, the resolution is correct. Issues which are not closed can be reopened.

Activity

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Ralf Joachim added a comment -

Udai created a series of howto documents about setting up Castor with eclipse and about execution of Castor's JDO test suites based on the introduction from me.

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Ralf Joachim added a comment - Udai created a series of howto documents about setting up Castor with eclipse and about execution of Castor's JDO test suites based on the introduction from me.
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Ralf Joachim added a comment -

To get familiar with external interfaces of Castor and also the codeing conventions I suggested Udai to meigrate soem test cases from old to new test suite.

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Ralf Joachim added a comment - To get familiar with external interfaces of Castor and also the codeing conventions I suggested Udai to meigrate soem test cases from old to new test suite.
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Ralf Joachim added a comment -

Udai and I agreed on the following schedule for the implementation phase.

Coding Phase I (Starts at May 26.)
----------------------------------------------------------------------

Week I and II (26 May - 7 June)
"""""""""""""""""""""""""""""""
Extract current Castor OQL BNF from parser and lexer source code of org.exolab.castor.jdo.oql package. Improve current parser tests to verify any possible syntax against current parser to verify that BNF is correct.

Divide EJB QL BNF of EJB 3.0 specification given at the end of chapter 4.12 into smaller parts. First part starts with very simple select statements. The other parts add more and more features until full EJB QL support.

Analysis find the parser generator that best suits the needs to cerate parser for Castor OQL and EJB QL.

Define features and requirements for "Query Objects" and Castor interface to use them.

Week III (8 June - 14 June)
"""""""""""""""""""""""""""
Create UML diagrams for "Query Objects"

Week IV (15 June - 21 June)
"""""""""""""""""""""""""""
Start implementation of "Query Objects" for simple "SELECT" statement including junit test cases. Create parser that translates simple "SELECT" queries into "Query Objects". Integrate "Query Objects" with Castor and verify that things are working as expected against various database engines.

Week V (22 June - 28 June)
""""""""""""""""""""""""""
Extend "Query Objects" and parser to support "ORDER BY" clauses.

Week VI (29 June - 5 July)
""""""""""""""""""""""""""
Reserved for refactorings and code improvements.

----------------------------------------------------------------------
Coding Phase I (Ends July 6.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
MID TERM EVALUATION (7 July - 14 July)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Coding Phase II (Starts July 15.)
----------------------------------------------------------------------

Week VII and VIII (15 July - 26 July)
"""""""""""""""""""""""""""""""""""""
Extend "Query Objects" and parser to support "WHERE" clauses.

Week IX and X (27 July - 2 Aug)
"""""""""""""""""""""""""""""""
Extend "Query Objects" and parser to support any missing clauses of Castor OQL.

----------------------------------------------------------------------
Coding Phase II (Ends August 10.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Suggested Pencils Down Week (11 August - 17 August)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Final Evaluations Phase (August 18 - September 1,)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Submit Code Samples to Google (September 3 - September 12)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Show
Ralf Joachim added a comment - Udai and I agreed on the following schedule for the implementation phase. Coding Phase I (Starts at May 26.) ---------------------------------------------------------------------- Week I and II (26 May - 7 June) """"""""""""""""""""""""""""""" Extract current Castor OQL BNF from parser and lexer source code of org.exolab.castor.jdo.oql package. Improve current parser tests to verify any possible syntax against current parser to verify that BNF is correct. Divide EJB QL BNF of EJB 3.0 specification given at the end of chapter 4.12 into smaller parts. First part starts with very simple select statements. The other parts add more and more features until full EJB QL support. Analysis find the parser generator that best suits the needs to cerate parser for Castor OQL and EJB QL. Define features and requirements for "Query Objects" and Castor interface to use them. Week III (8 June - 14 June) """"""""""""""""""""""""""" Create UML diagrams for "Query Objects" Week IV (15 June - 21 June) """"""""""""""""""""""""""" Start implementation of "Query Objects" for simple "SELECT" statement including junit test cases. Create parser that translates simple "SELECT" queries into "Query Objects". Integrate "Query Objects" with Castor and verify that things are working as expected against various database engines. Week V (22 June - 28 June) """""""""""""""""""""""""" Extend "Query Objects" and parser to support "ORDER BY" clauses. Week VI (29 June - 5 July) """""""""""""""""""""""""" Reserved for refactorings and code improvements. ---------------------------------------------------------------------- Coding Phase I (Ends July 6.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ MID TERM EVALUATION (7 July - 14 July) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Coding Phase II (Starts July 15.) ---------------------------------------------------------------------- Week VII and VIII (15 July - 26 July) """"""""""""""""""""""""""""""""""""" Extend "Query Objects" and parser to support "WHERE" clauses. Week IX and X (27 July - 2 Aug) """"""""""""""""""""""""""""""" Extend "Query Objects" and parser to support any missing clauses of Castor OQL. ---------------------------------------------------------------------- Coding Phase II (Ends August 10.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Suggested Pencils Down Week (11 August - 17 August) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Final Evaluations Phase (August 18 - September 1,) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Submit Code Samples to Google (September 3 - September 12) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
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Udai Gupta added a comment -

I have created the first four sub - task I will be working on in the same order.

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Udai Gupta added a comment - I have created the first four sub - task I will be working on in the same order.
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Ralf Joachim added a comment -

Issue castor-324 have previously been used to discuss about refactoring OQL query engine. It contains various useful information so I decided to link it from here.

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Ralf Joachim added a comment - Issue castor-324 have previously been used to discuss about refactoring OQL query engine. It contains various useful information so I decided to link it from here.
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Ralf Joachim added a comment -

Created a branch starting with 1.2 for this issue and its subtasks called "query_engine"

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Ralf Joachim added a comment - Created a branch starting with 1.2 for this issue and its subtasks called "query_engine"
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Ralf Joachim added a comment -

Patch with all changes of GSoC 2008 project

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Ralf Joachim added a comment - Patch with all changes of GSoC 2008 project
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Udai Gupta added a comment -

File to be submitted at GSoC 2008 code base.

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Udai Gupta added a comment - File to be submitted at GSoC 2008 code base.
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Ralf Joachim added a comment -

Query objects created during GSoC 2008 have been added to trunk with CASTOR-2796. The parser still waits on its integration. In addition the translation from query objects to SQL is still missing.

Show
Ralf Joachim added a comment - Query objects created during GSoC 2008 have been added to trunk with CASTOR-2796 . The parser still waits on its integration. In addition the translation from query objects to SQL is still missing.

People

  • Assignee:
    Ralf Joachim
    Reporter:
    Ralf Joachim
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Dates

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    Updated:
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