Granted Patent B2

US 8,700,566 · App. 12/563,637 · Granted Apr 15, 2014

Abstract

Claims (82)

1. A computer programmed to perform an offline data entry database (DEDB) restructure operation, the operation comprising:

identifying an online source DEDB having a first structure;

identifying an offline shadow DEDB having a second structure that differs from the first structure;

registering one or more areas of the source DEDB with a change capture module prior to copying data from the source DEDB to the offline shadow DEDB, an area comprising a specified number of units of work (UOWs), a UOW being a region contained in a specified number of storage blocks;

copying data from the one or more registered areas of the source DEDB into the offline shadow DEDB in units of work, wherein the copying of each unit of work (UOW) occurs sequentially so that copying begins after the preceding UOW has been written to the offline shadow DEDB;

identifying a modification to the source DEDB occurring during the act of copying;

determining whether the modification is directed to a registered area;

applying the modification to the offline shadow DEDB while keeping the source DEDB online;

quiesceing the source DEDB;

taking the source DEDB offline;

applying any additional modifications made to the source DEDB that have not been applied to the offline shadow DEDB;

swapping the offline shadow DEDB for the source DEDB; and

putting the offline shadow DEDB online, wherein the offline shadow DEDB replaces the source DEDB as an online DEDB.

2. The computer of claim 1 , wherein identifying the offline shadow DEDB comprises:

defining the second structure; and

allocating the offline shadow DEDB.

3. The computer of claim 1 , wherein the areas registered represent less than the entire source DEDB.

4. The computer of claim 1 , the operation further comprising:

determining whether a sufficiently small number of modifications await to be applied to the offline shadow DEDB; and

performing the quiescing, the applying, the, and

putting the offline shadow DEDB online when it is determined that a sufficiently small number of modifications await to be applied to the offline shadow DEDB.

5. The computer of claim 1 , wherein the program to perform the offline DEDB restructure operation comprises a member of an IMSPlex.

6. The computer of claim 1 , wherein copying data from the source DEDB into the offline shadow DEDB comprises:

quiescing a first unit of work (UOW) in the source DEDB;

notifying the change capture module that the first UOW has been copied to the offline shadow DEDB;

reading the first UOW from the source DEDB at a first time;

writing the first UOW into the offline shadow DEDB; and

releasing the first UOW so that it may be updated in the source DEDB.

7. The computer of claim 6 , wherein applying the identified modifications comprises incorporating, into the offline shadow DEDB, at least one modification to a second UOW in the source DEDB, wherein the second UOW was copied into the offline shadow DEDB before the first time.

8. The computer of claim 6 , wherein the modification is to a second source DEDB UOW, and wherein

the second source DEDB UOW was copied into the offline shadow DEDB at a second time,

the second time occurring before the first time, and

the modification to the second source DEDB UOW occurring after the second time and before the first time.

9. The computer of claim 8 , wherein applying the modification comprises:

identifying a first update portion of the modification to the second source DEDB UOW, the first update portion comprising a key and content;

extracting the key;

identifying a location within the offline shadow DEDB based on application of a randomizer function to the extracted key; and

writing the content into the offline shadow DEDB at the identified location.

10. A program storage device comprising instructions for causing a programmable control device to perform the offline data entry database (DEDB) restructure operation of claim 1 .

11. The program storage device of claim 10 , wherein the instructions for causing the programmable control device to perform the act of copying comprises instructions for causing the programmable control device to:

quiesce a first unit of work (UOW) in the source DEDB;

read the first UOW from the source DEDB at a first time;

write the first UOW into the offline shadow DEDB; and

release the first UOW so that it may be updated in the source DEDB.

12. The program storage device of claim 11 , wherein the instructions for causing the programmable control device to perform the act of identifying modifications to the source DEDB comprises instructions for causing the programmable control device to identify a modification to a second source DEDB UOW, wherein:

the second source DEDB UOW was copied into the offline shadow DEDB at a second time,

the second time occurring before the first time, and

the modification to the second source DEDB UOW occurring after the second time and before the first time.

13. A networked computer system comprising a plurality of computers communicatively coupled, at least one of the plurality of computers programmed to perform at least a portion of the offline data entry database (DEDB) restructure operation of claim 1 , wherein the entire offline data entry database (DEDB) restructure operation of claim 1 is performed collectively by the plurality of computers.

14. A computer system comprising:

a first storage device having stored therein an online source data entry database (DEDB) having a first structure;

a database management system (DBMS) communicatively coupled to the first storage device, wherein the DBMS is configured to modify the source DEDB;

a second storage device having stored therein an offline shadow DEDB having a second structure that differs from the first structure;

at least one processor; and

a memory storing instructions that, when executed by at least one processor, cause the computer system to perform operations comprising:

registering one or more areas of the source DEDB with a change capture module prior to reading content from the source DEDB in units of work,

reading content from the one or more areas of source DEDB in units of work, wherein a unit of work (UOW) is a region contained in a specified number of storage blocks and wherein a specified number of UOWs comprise an area of the source DEDB;

receiving notification of modifications to the source DEDB from the DBMS;

writing data to the offline shadow DEDB based on the source DEDB content and the modifications to the source DEDB, wherein the modifications are applied to the offline shadow DEDB when the modifications are directed to the one or more areas registered with the change capture module;

quiesceinq the source DEDB;

taking the source DEDB offline;

applying any additional modifications made to the source DEDB that have not been applied to the offline shadow DEDB;

swapping the offline shadow DEDB for the source DEDB; and

putting the offline shadow DEDB online, wherein the offline shadow DEDB replaces the source DEDB as an online DEDB.

15. The computer system of claim 14 , wherein the computer system includes an IMSPlex, where the DBMS is associated with a first computing device of the computer system and the computer system further includes a second DBMS communicatively coupled to the source DEDB and associated with a second computing device.

16. The computer system of claim 15 , wherein receiving notification of modifications to the source DEDB further includes receiving notification of modifications to the source DEDB by the second DBMS.

17. The computer system of claim 14 , wherein writing data to the offline shadow DEDB based on the source DEDB content comprises:

quiescing a first unit of work (UOW) in the source DEDB;

notifying the change capture module that the first UOW has been copied to the offline shadow DEDB;

reading the first UOW from the source DEDB;

writing the first UOW into the offline shadow DEDB; and

releasing the first UOW so that it may be updated in the source DEDB.

18. The computer system of claim 17 , wherein writing data to the offline shadow DEDB based on the source DEDB content and the modifications comprises:

receiving a modification to a second source DEDB UOW;

determining, using the change capture module, whether the second source DEDB UOW has been copied to the offline shadow DEDB;

ignoring the update when the second source DEDB UOW has not been copied to the offline shadow DEDB; and

applying the modification to a UOW of the offline shadow DEDB when the second source DEDB UOW has been copied to the offline shadow DEDB.

19. The computer system of claim 14 , wherein applying a modification to the offline shadow DEDB comprises:

extracting a key from an update portion of the modification;

applying the key to a randomizer function for the offline shadow DEDB to determine a unique location in the offline shadow DEDB; and

writing the modification to the unique location.

20. The computer system of claim 14 , wherein the first structure differs from the second structure in a randomizer function used by the database, the randomizer function selecting an area of the DEDB and a root anchor point (RAP) within the area as a location for a database record.

Assignments (12)