System and method for delayed fetching of designated members of a user defined type

• US 7,548,901 B2
• Filed: 06/29/2004
• Issued: 06/16/2009
• Est. Priority Date: 06/29/2004
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Krishnamoorthy, Ganapathy, Zabokritski, Eugene, Nair, Giri, Ashwin, Shrinivas, Kleinerman, Christian
• Primary Examiner(s): Alam; Hosain T
• Assistant Examiner(s): JOHNSON, JOHNESE T
• Application Number:
  US10/879,326
• Publication Number:
  US 20050289160A1
• Time in Patent Office: 1,813 Days
• Field of Search: 707/3
• US Class Current: 1/1
• CPC Class Codes: G06F 16/24547 Optimisations to support specific applications; Extensibility of optimisers
• CPC Class Codes: G06F 16/24557 Efficient disk access during query execution
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation

Abstract

A number of members of a user defined type may be designated as delayable members. During an initial fetch of the type, the type may be returned from the database without the delayable members, thereby preserving valuable bandwidth and reducing the amount of time required to perform the initial fetch. Upon request, selected delayable members may be re-fetched from the database at a later time without returning the other members provided during the initial fetch.

Claims

1. A system for delayed fetching of a designated member of a user defined type comprising the designated member and a non-designated member, the system comprising:

a processor to execute computer-executable instructions; and

memory having stored therein computer-executable instructions for performing steps comprising;

receiving from a client an initial fetch request to fetch the user defined type from a data store, the initial fetch request comprising instructions to fetch the non-designated member of the user defined type and to delay fetching of the designated member of the user defined type;

examining a UPDATE SEQUENCE MARKER maintained by the data store to identify a time when the initial fetch request was received by the data store;

generating a container reference to the user defined type that identifies a path to the user defined type within a data store;

retrieving a serialized representation of the user defined type from the data store;

removing only the designated member from the serialized representation whereby, after the removal, the non-designated member remains within the serialized representation;

attaching the container reference to the serialized representation;

generating a query response comprising the serialized representation that comprises the non-designated member, the query response further comprising the attached container reference and the UPDATE SEQUENCE MARKER;

sending the query response to the client;

receiving from the client a re-fetch request to re-fetch the designated member, the re-fetch request comprising the container reference and the UPDATE SEQUENCE MARKER the re-fetch request indicating a selectable first mode operating to retrieve delayed members at the time of the re-fetch operation and a selectable second mode operating to retrieve delayed members as of the time when the initial fetch was executed;

retrieving from the data store a version of the designated member identified by the UPDATE SEQUENCE MARKER based upon a selected mode; and

returning the retrieved version of the designated member to the client.

2. A computer readable medium having stored thereon computer executable instructions far delayed fetching of a designated member of a user defined type comprising the designated member and a non-designated member, the computer executable instructions comprising:

receiving from a client an initial fetch request to fetch the user defined type from a data store, the initial fetch request comprising instructions to fetch the non-designated member of the user defined type and to delay fetching of the designated member of the user defined type;

examining a UPDATE SEQUENCE MARKER maintained by the data store to identify a time when the initial fetch request was received by the data store;

generating a container reference to the user defined type that identifies a path to the user defined type within a data store;

retrieving a serialized representation of the user defined type from the data store;

removing only the designated member from the serialized representation whereby, after the removal, the non-designated member remains within the serialized representation;

attaching the container reference to the serialized representation;

generating a query response comprising the serialized representation that comprises the non-designated member, the query response further comprising the attached container reference and the UPDATE SEQUENCE MARKER;

sending the query response to the client;

receiving from the client re-fetch request to re-fetch the designated member, the re-fetch request comprising the container reference and the UPDATE SEQUENCE MARKER, the re-fetch request indicating a selectable first node operating to retrieve delayed members at the time of the re-fetch operation and a selectable second mode operating to retrieve delayed members as of the time when the initial fetch was executed;

retrieving from the data store a version of the designated member identified by the UPDATE SEQUENCE MARKER based upon a selected node; and

returning the retrieved version of the designated member to the client.

3. A method for delayed fetching of a designated member of a user defined type comprising the designated member and a non-designated member, the method comprising:

receiving from a client initial fetch request to fetch the user- defined type from a data store, the initial fetch request comprising instructions to fetch the non-designated member of the user defined type and to delay fetching of the designated member of the user defined type;

examining a UPDATE SEQUENCE MARKER maintained by the data store to identify a time when the initial fetch request was received by the data store,

generating a container reference to the user defined type that identifies a path to the user defined type within a data store;

retrieving a serialized representation of the user defined type from the data store;

removing only the designated member from the serialized representation whereby, after the removal, the non-designated member remains within the serialized representation;

attaching the container reference to the serialized representation;

generating a query response comprising the serialized representation that comprises the non-designated member, the query response further comprising the attached container reference and the UPDATE SEQUENCE MARKER;

sending the query response to the client;

receiving from the client a re-fetch request to re-fetch the designated member, the re-fetch request comprising the container reference and the UPDATE SEQUENCE MARKER, the re-fetch request indicating a selectable first node operating to retrieve delayed members at the time of the re-fetch operation and a selectable second node operating to re-fetch delayed member as of the time when the initial fetch was executed;

retrieving from the data store a version of the designated member identified by the UPDATE SEQUENCE MARKER based upon a selected node; and

returning the retrieved version of the designated member to the client.

4. The method of claim 3, further comprising ensuring the security of the container reference prior to attaching it to the serialized representation.

5. The method of claim 3, further comprising:

receiving a re-serialized representation of the user defined type wherein the designated member is replaced by context information comprising the container reference and an individual member path to the designated member;

replacing the context information with the designated member, the designated member identified based on the context information; and

storing the re-serialized representation at the data store.

6. The method of claim 3, further comprising:

receiving context information comprising the container reference and an individual member path to the designated member and receiving a metadata annotation identifying the context information as a path to a location of the designated member within the data store;

replacing the context information with the designated member, the designated member identified based on the context information; and

storing the designated member at the data store.