Hi IoTDB community, As the end of 2025 approaches, here is a consolidated IoTDB development update within Timecho covering the past two months. Some of the work listed below has already been merged and is in active use, while other items are still ongoing or under development.
Apologies for the delayed sync, and thank you all for the continuous support and contributions throughout the year. Query & Engine Improvements - Added system tables for: * Top-10 slowest SQL statements * SQL execution time statistics * Node connection status - Significantly optimized performance of show/count timeseries where timePredicate scanning in memtables. - Fixed multiple query-related issues, including: * Incorrect results in table mode with group by + order by + limit * Errors when ORDER BY is used without PARTITION BY in table/window functions * UNION-related aggregation bugs * Tree mode UDAF-median array out-of-bounds issue * group by time with overlapping windows in memtable scan - Improved aggregation performance after UNION operations. Stability & Memory - Fixed memory pool inconsistency when concurrent queries access the same TVList. - Fixed memory leaks caused by network failures leading to full queues and WAL backlog not decreasing after recovery. - Improved Tablet memory accounting and DualKeyCache write efficiency. - Fixed SchemaCache memory calculation and inconsistent memory block naming. Pipe & Data Synchronization - Added interface to collect Tablets directly from Pipe Events. - Improved Pipe handling for: * Temporary OOM situations * Authorization failures on receiver side * Concurrent template setting * Mods handling when splitting TsFiles - Fixed multiple Pipe-related NPEs, logging issues, and case-sensitivity bugs. - Added double-living option for Pipe historical data synchronization. - Adjusted retry and waiting strategies for temporary failures. Cluster & System - Upgraded Apache Ratis to 3.2.1. - Improved robustness of CI Procedure recovery and lock handling. - Optimized load and region migration concurrency logic. - Fixed multiple load-related issues, including mods handling, relative paths, file copy order, and aligned device attributes. - Reduced noisy logs during merge service shutdown and connection resets. - Improved error handling when disk space is insufficient. - Fixed security issues such as plaintext password exposure in show configuration. - Added support to modify encoding/compression for existing time series in tree mode. External Integration - Optimized OPC UA external service, including simultaneous value and quality code pushing. - Optimized MQTT write path with batching logic. Ongoing / Planned Work - Disk space usage statistics: initial design completed. - External service creation support: initial design completed. - OBJECT data type: under active development. Thank you all for your reviews, discussions, and contributions in 2025. Wishing everyone a happy New Year and a productive 2026! Best regards, Pengcheng The Timecho Team
