CelesDb Overview

CelesDb is a custom-built database designed to optimize the storage and retrieval of blockchain state data for the Celestium network. Unlike traditional key-value databases commonly used in blockchain clients, CelesDb is specifically tailored to meet the demands of high-throughput parallel execution and asynchronous state management.

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Motivation for CelesDb

Most Ethereum clients rely on general-purpose key-value stores like LevelDB, RocksDB, or LMDB, which internally use data structures such as B-Trees or LSM-Trees. However, Ethereum itself represents state using a Merkle Patricia Trie (MPT). This results in a mismatch between the underlying storage structure and the logical state representation, causing performance inefficiencies.

CelesDb addresses this by natively implementing the Patricia Trie structure for both in-memory and on-disk storage. This direct mapping eliminates the overhead of embedding one data structure within another, significantly improving read and write performance.

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Key Features of CelesDb

Feature	Description
Native Patricia Trie Implementation	CelesDb stores blockchain state directly as a Patricia Trie on disk and in memory, optimizing access times.
Asynchronous I/O (async I/O)	Supports non-blocking database operations using modern system calls (e.g., io_uring on Linux).
Parallel State Access	Designed to support parallel transaction execution, allowing concurrent reads and writes.
Low-latency Performance	Bypasses filesystem caching in certain cases for direct I/O access, reducing overhead.
Optimized for High Throughput	Supports batch writes and parallel state reads to match the demands of Celestium’s parallel execution model.

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Asynchronous I/O (async I/O)

A critical feature of CelesDb is its support for asynchronous I/O operations. Since Celestium executes multiple transactions in parallel, traditional blocking I/O would cause performance bottlenecks. Instead, CelesDb uses Linux’s io_uring interface to enable non-blocking, kernel-level asynchronous I/O operations. This allows:

• Multiple I/O requests to be initiated simultaneously.

• CPU resources to be used for other tasks while waiting for disk operations to complete.

• Reduced context switching compared to traditional thread-based blocking I/O.

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How CelesDb Supports Parallel Execution

Parallel transaction execution requires efficient concurrent access to state. CelesDb is designed to support:

1. Concurrent Reads: Multiple transactions can read state simultaneously without blocking each other.

2. Optimistic Writes: Transactions write to isolated state buffers during execution, reducing conflicts.

3. State Merging: After transactions execute, CelesDb merges state changes in block order to ensure deterministic final state.

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Low-level Optimizations

Optimization	Description
Direct I/O Access	Avoids OS-level filesystem caching in certain cases to reduce overhead.
Batch Writes	Bundles multiple state changes into a single write operation for efficiency.
Memory-efficient Trie Nodes	Stores Patricia Trie nodes in compact formats, minimizing memory and disk usage.

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Benefits of CelesDb

• Faster Block Processing: Reduces state access latency during parallel and optimistic execution.

• Improved Scalability: Handles high transaction throughput by supporting parallel state access.

• Lower Resource Usage: Efficient memory and disk management tailored for blockchain workloads.

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Comparison with Traditional Solutions

Aspect	CelesDb	LevelDB / RocksDB
Data Structure	Native Patricia Trie	LSM-Tree / B-Tree
Async I/O Support	Full support via io_uring	Limited / None
Parallel Access	Built-in support for parallel reads/writes	Designed for sequential access
Blockchain State Efficiency	Optimized for Patricia Trie-based state storage	General-purpose storage

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Future Development

CelesDb will continue to be improved with:

• Further optimizations for Patricia Trie compaction.

• Caching strategies to reduce disk access for frequently read state.

• Cross-platform async I/O support beyond Linux (e.g., Windows IOCP).

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Final Thoughts

CelesDb is a cornerstone innovation of the Celestium blockchain, enabling high-performance state management that aligns with parallel and asynchronous execution models. This custom database ensures that Celestium can achieve scalability and efficiency without compromising on Ethereum-compatible state guarantees.