Non-disruptive Database Backup During Online Reorganization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current database management systems do not allow for the creation of backup copies during online reorganization, as it disrupts the reorganization process and prevents access to the dataset, due to the need for a stable cursor and lack of mechanisms for registering source and target datasets.
Innovation Solution
A method to create a non-disruptive backup copy of a dataset undergoing online reorganization by reading an input image copy, determining a cursor value associated with reorganization, and producing a backup copy that includes a first area to reconstruct the target image copy and a second area to reconstruct the source image copy based on the cursor, allowing for backup without disrupting the reorganization process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a backup copy is created during online reorganization, then backup availability is improved, but system stability deteriorates due to cursor instability
Solution Approach 1:
The backup copy is divided into two distinct areas: a first area containing blocks from the source dataset and a second area containing blocks from the target dataset. The cursor value segments the block sequence into two portions, allowing the backup to capture the reorganization state without requiring complete cursor stability throughout the entire dataset.
Solution Approach 2:
The backup copy structure dynamically adapts to the changing cursor position during online reorganization. By incorporating blocks from both source and target datasets in different areas, the backup remains valid even as the cursor moves and reorganization progresses, eliminating the need for a static stable cursor.
2Productivity
If online reorganization is performed, then dataset maintenance is improved, but backup creation capability deteriorates
Solution Approach 1:
The backup copy serves multiple functions simultaneously: it captures the dataset state for backup purposes while also documenting the reorganization progress. The structured format with source and target areas provides both backup functionality and reorganization tracking, eliminating the need to pause reorganization for backup operations.
3Loss of information
If a complete image copy is made during reorganization, then backup completeness is improved, but reorganization disruption increases
Solution Approach 1:
The backup copy is constructed by gathering blocks from both source and target datasets according to the current cursor position, rather than attempting to create a complete copy of the entire reorganized dataset. This preliminary capture of relevant blocks in a structured format achieves sufficient backup completeness without requiring the reorganization to complete first.
Data Source
AI summary
Various embodiments of a computer system and computer program product backup a dataset. An input image copy of the dataset is read, wherein the input image copy is prior to a start of dataset reorganization. A cursor value associated with reorganization of said dataset is determined. A backup copy is produced based on the input image copy, the changes from the log and the cursor value.