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Xiangdong Huang updated COMDEV-402: ----------------------------------- Labels: IoTDB (was: IoTDB gsoc2021 mentor) > Apache IoTDB: Metadata (Schema) Storage Engine > ---------------------------------------------- > > Key: COMDEV-402 > URL: https://issues.apache.org/jira/browse/COMDEV-402 > Project: Community Development > Issue Type: Task > Components: GSoC/Mentoring ideas > Reporter: Xiangdong Huang > Priority: Major > Labels: IoTDB > > Apache IoTDB [1] is an Open Source IoT database designed to meet the rigorous > data, storage, and analytics requirements of large-scale Internet of Things > (IoT) and Industrial Internet of Things (IIoT) applications. > Different with traditional relational databases, IoTDB uses tree-based > structure in memory to manage the schema (a.k.a, metadata), and use a > Write-Ahead-Log-like file structure to persist the schema. > Now, each time series will take about 300 Bytes in memory. However, an IoTDB > instance may manage more than 100 million time series, which may take more > than 30GB memory. > Therefore, we'd like to re-design the schema management module. > 1. File: Persist the tree on disk like a b-tree. > 2. WAL: implement the WAL of the metadata. So we can update the tree on disk > in batch, rather than one operation by one. > 3. Cache: we may have no memory to load the whole tree. So a cache is needed > and query from the tree on disk is needed. > What knowledge you need to know: > 1. Java > 2. Basic design idea about Database [2] > [1] https://iotdb.apache.org > [2] > http://pages.cs.wisc.edu/~dbbook/openAccess/firstEdition/slides/pdfslides/mod2l1.pdf -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@community.apache.org For additional commands, e-mail: dev-h...@community.apache.org