Database recovery and index rebuilds

Patent metadata

Field	Value
Publication number	US-10140189-B2
Application number	US-201514697794-A
Country	US
Kind code	B2
Filing date	Apr 28, 2015
Priority date	Apr 28, 2015
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

A computer-implemented method for recovering data and concurrently rebuilding indexes for the recovered data in a database for a system configured to store fewer than all indexes in backup files may include copying data from one or more database files and storing the copied data to one or more backup files. A recovery manager executing on a processor may read the copied data from the one or more backup files and write the copied data to the one or more database files, wherein the data is recovered to the one or more database files. In response to the reading, an index manager executing on the processor may initiate a rebuilding of one or more indexes for the copied data at substantially the same time as the reading of the copied data.

First claim

What is claimed is:

1. A computer-implemented method for recovering data and concurrently rebuilding indexes for the recovered data in a database for a system configured to store fewer than all indexes in backup files, comprising: copying data from one or more database files and storing the copied data to one or more backup files; reading the copied data from the one or more backup files, by a recovery manager executing on a processor, and writing the copied data to the one or more database files by the recovery manager, wherein the data is recovered to the one or more database files, and wherein one or more indexes are not recovered; in response to and at substantially the same time as the reading, initiating a rebuilding of the one or more indexes for the copied data, by an index manager executing on the processor, wherein initiating the rebuilding of the one or more indexes at substantially the same time reduces a quantity of 1/0 operations needed for data recovery; and in response to finishing the rebuilding of the one or more indexes, applying a first set of log records from a transaction log to the one or more database files, the one or more log records specify a particular point in time for recovery.

2. The method of claim 1 , wherein the storing of the copied data to one or more backup files includes storing an image copy of the data to a sparse backup file, and storing a log record of the data to a transaction log, the sparse backup file includes an empty pages of data and is not allocated disk space for the data at a first time, wherein in response to a page of the one or more database files being modified at a second subsequent time, a size of the sparse file expands such that the sparse backup file pages are no longer empty.

3. The method of claim 1 , wherein initiating of the rebuilding of one or more indexes includes receiving one or more sorted index keys by the index manager, and rebuilding the one or more indexes in response to the receiving of the one or more sorted index keys.

4. The method of claim 1 , wherein the rebuilding of the one or more indexes finishes at substantially the same time as the writing of the copied data.

5. The method of claim 1 , wherein the reading the copied data from the one or more backup files by the recovery manager includes: reading an image copy of one or more data pages of the copied data from a sparse backup file, the reading of the image copy further comprising: parsing the one or more data pages from the image copy into one or more database records, extracting one or more index keys from the one or more database records, and sorting the one or more index keys in preparation initiating of the rebuilding of one or more indexes; and reading one or more log records from a transaction log, wherein the one or more log records specify a particular point in time for recovery.

6. The method of claim 5 , wherein the writing includes writing the image copy from the sparse backup file to the one or more database files and applying the one or more log records from the transaction log to the one or more database files.

7. The method of claim 6 , wherein the reading of the image copy and the reading of the one or more log records is initiated at a first time, initiating of the rebuilding of one or more indexes occurs at a second time, and the applying of one or more log records is initiated at a third time, the third time being subsequent to the second time and the second time being subsequent to the first time.

Assignees

• IBM

Inventors

• Fang Min
• Jin Di
• Shi zhen yu
• Slinger Nigel G
• Wang Shu
• Zheng li fei
• Zhu wen jie

Classifications

• G06F16/2358

  Change logging, detection, and notification (replication G06F16/27) · CPC title

• G06F16/2272

  Management thereof · CPC title

• G06F11/1446

  Point-in-time backing up or restoration of persistent data · CPC title

• G06F11/1469

  Backup restoration techniques · CPC title

• G06F11/1451

  by selection of backup contents · CPC title