Fine-Grain Locking for Semantic Database Index Updates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current indexing systems for semantic databases face inefficiencies in updating indexes due to the need for exclusive access, leading to prolonged downtime and inconsistencies during the addition of new triples, which affects the performance of search queries in large datasets.
Innovation Solution
The implementation of fine-grain locking within the indexing system allows concurrent access by locking only small portions of the index during updates, enabling readers and writers to operate simultaneously without requiring exclusive access to the entire index, thereby reducing downtime and maintaining data consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If exclusive access locking is used during index updates, then data consistency is maintained, but search query performance deteriorates due to prolonged downtime and blocked concurrent access
Solution Approach 1:
The patent segments the index into multiple independent portions (index segments), each protected by its own lock. This allows updates to occur on one segment while other segments remain accessible for queries, eliminating the need for exclusive access to the entire index and enabling concurrent read operations during index maintenance.
Solution Approach 2:
The patent implements dynamic locking where locks are acquired and released on specific index segments only when needed for updates, rather than maintaining static exclusive locks on the entire index. This dynamic approach allows the system to switch between read and write access on different segments at different times, improving overall system throughput and query performance during index maintenance operations.
2Productivity
If fine-grain locking is implemented to allow concurrent access, then search query performance improves, but index update complexity increases
Solution Approach 1:
By dividing the index into manageable segments with individual locks, the patent reduces the scope of locking operations. Each update operation only needs to acquire locks on the specific segments being modified, simplifying the locking logic compared to managing locks on the entire index structure.
Solution Approach 2:
The patent introduces an intermediary locking mechanism that mediates between readers and writers on specific index segments. This intermediary layer manages the complexity of concurrent access control, providing a standardized interface for acquiring and releasing locks while handling the underlying synchronization details.
3Reliability
If the entire index is locked during updates, then data consistency is ensured, but the overhead of waiting for updates increases
Solution Approach 1:
The patent segments the index into multiple independent portions, each with its own lock. This allows readers to access unlocked segments immediately without waiting for updates on other segments, significantly reducing the waiting overhead while maintaining data consistency through fine-grained locking on the specific segments being updated.
Data Source
AI summary
A system for updating an index into a tuple table of tuples is provided. An indexing system updates an index into a tuple table using fine-grain locking of the index. The index includes a values table with an entry for each index value of an index field that references a value-tuple table that includes, for each tuple with the index value, a row that identifies a tuple of the tuple table with that indexed value. After a new tuple is added to the tuple table with a value, the index is updated by locking the entry in the values table, updating the value-tuple table for the value, and then unlocking the entry. When the index is accessed for locating tuples with a value, the accessor locks the entry in the values table for the value, uses the value-tuple table to locate the tuples, and unlocks the entry.