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TencentDB TDStore Online DDL: Technological Evolution and Innovations Background & Challenges
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....encentDB TDStore Online DDL: Technological Evolution and Innovations Background & Challenges<BR>PTI News<BR>Dated:- 22-4-2025<BR>PTI<BR>SHENZHEN, China, April 22, 2025 /PRNewswire/ -- Traditional single-node databases (e.g., MySQL) use OnlineDDL and third-party tools (e.g., pt-osc) to enable lock-free schema changes, but face performance bottlenecks and struggle in distributed environments. Tencen....
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....t Cloud's TDStore, a financial-grade distributed database, addresses these challenges with groundbreaking innovations: Core Technological Innovations 1. Multi-Version Schema Mechanism a. Introduces schema versioning to enable metadata-only modifications in seconds (e.g., adding trailing columns, extending fields). Historical data automatically fills default values, ensuring backward compatibility.....
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.... 2. Concurrency Control & State Transition a. Thomas Write Rule: Reduces transaction conflicts by ignoring stale writes, improving DDL-DML parallelism. b. Google F1 Phased State Design: Divides DDL into three stages (delete-only ? write-only ? final) to ensure global consistency and smooth transitions. 3. Write Fence Mechanism a. Validates request versions at the storage layer, allowing write....
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....s only between adjacent states to eliminate data inconsistency risks. 4. Fast OnlineDDL Acceleration a. Distributed Parallel Backfilling: Splits data into SST files for multi-node parallel ingestion via bulk load, bypassing timestamp comparisons to achieve 13x performance gains (10 minutes vs. 2.3 hours). Practices & Optimizations 1. Performance Comparison a. Traditional Mode (single-node): 16....
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.... threads took 2.3 hours. b. Fast Mode (multi-node): 48 threads completed in 10 minutes, showcasing significant efficiency improvements. 2. Partitioning Best Practices a. Large Tables: Use HASH/KEY partitioning to distribute data evenly, enabling parallel DDL execution. b. Cold/Hot Separation: Combine RANGE+HASH secondary partitioning for rapid cleanup and elastic scaling. c. High Concurrency:....
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.... Align partition keys with frequent query fields; set partition count as multiples of node numbers. 3. Key Parameter Configuration a. max_parallel_ddl_degree: Increase parallel threads (= total node CPUs). b. tdsql_ddl_fillback_mode: Enable IngestBehind mode to unlock multi-node parallel acceleration. Business Value & Future Roadmap • Validated Use Cases: Achieved zero downtime in PB-scale ....
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....financial systems, with 10x faster execution than third-party tools. • Upcoming Enhancements: • Optimize partitioned table Copy Table and index backfilling for ordinary tables. • Support ultra-large-scale (tens of TB) workloads and hybrid HTAP architectures. Conclusion TDStore overcomes traditional OnlineDDL limitations through distributed architecture innovations and engineering pract....
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....ices, delivering high-performance, secure, and seamless schema change capabilities for financial-grade scenarios. It empowers enterprises to tackle massive data challenges effectively. #DistributedDatabase #TencentCloud #TencentDB #TDSQL #Tencent Cloud BigData (Disclaimer: The above press release comes to you under an arrangement with PRNewswire and PTI takes no editorial responsibility for the ....
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....same.). PTI PWR PWR<BR> News - Press release - PIB ....