RocksDB
SQLite
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RocksDB | SQLite | |
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43 | 39 | |
27,285 | 5,395 | |
1.1% | - | |
9.8 | 0.0 | |
7 days ago | 8 days ago | |
C++ | C | |
GNU General Public License v3.0 only | GNU General Public License v3.0 or later |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
RocksDB
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How to choose the right type of database
RocksDB: A high-performance embedded database optimized for multi-core CPUs and fast storage like SSDs. Its use of a log-structured merge-tree (LSM tree) makes it suitable for applications requiring high throughput and efficient storage, such as streaming data processing.
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Fast persistent recoverable log and key-value store
[RocksDB](https://rocksdb.org/) isn’t a distributed storage system, fwiw. It’s an embedded KV engine similar to LevelDB, LMDB, or really sqlite (though that’s full SQL, not just KV)
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The Hallucinated Rows Incident
To output the top 3 rocks, our engine has to first store all the rocks in some sorted way. To do this, we of course picked RocksDB, an embedded lexicographically sorted key-value store, which acts as the sorting operation's persistent state. In our RocksDB state, the diffs are keyed by the value of weight, and since RocksDB is sorted, our stored diffs are automatically sorted by their weight.
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In-memory vs. disk-based databases: Why do you need a larger than memory architecture?
The in-memory version of Memgraph uses Delta storage to support multi-version concurrency control (MVCC). However, for larger-than-memory storage, we decided to use the Optimistic Concurrency Control Protocol (OCC) since we assumed conflicts would rarely happen, and we could make use of RocksDB’s transactions without dealing with the custom layer of complexity like in the case of Delta storage.
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Local file non relational database with filter by value
I was looking at https://github.com/facebook/rocksdb/ but it seems to not allow queries by value, as my last requirmenet.
- Rocksdb over network
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How RocksDB Works
Tuning RocksDB well is a very very hard challenge, and one that I am happy to not do day to day anymore. RocksDB is very powerful but it comes with other very sharp edges. Compaction is one of those, and all answers are likely workload dependent.
If you are worried about write amplification then leveled compactions are sub-optimal. I would try the universal compaction.
- https://github.com/facebook/rocksdb/wiki/Universal-Compactio...
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What are the advantages of using Rust to develop KV databases?
It's fairly challenging to write a KV database, and takes several years of development to get the balance right between performance and reliability and avoiding data loss. Maybe read through the documentation for RocksDB https://github.com/facebook/rocksdb/wiki/RocksDB-Overview and watch the video on why it was developed and that may give you an impression of what is involved.
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We’re the Meilisearch team! To celebrate v1.0 of our open-source search engine, Ask us Anything!
LMDB is much more sain in the sense that it supports real ACID transactions instead of savepoints for RocksDB. The latter is heavy and consumes a lot more memory for a lot less read throughput. However, RocksDB has a much better parallel and concurrent write story, where you can merge entries with merge functions and therefore write from multiple CPUs.
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Google's OSS-Fuzz expands fuzz-reward program to $30000
https://github.com/facebook/rocksdb/issues?q=is%3Aissue+clic...
Here are some bugs in JeMalloc:
SQLite
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A SQLite extension that brings column-oriented tables to SQLite
If you are into alternative storage engines for SQLite, there is also an LSM (Log-Structured Merge-tree) extension in the main repository that is not announced nor documented but seems to work. It’s based on the SQLite 4 project.
https://github.com/sqlite/sqlite/tree/master/ext/lsm1
https://www.charlesleifer.com/blog/lsm-key-value-storage-in-...
- SQLite License
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Ask HN: Where do I find good code to read?
The sqlite code base is really well done. Lots of documentation.
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Show HN: I wrote a RDBMS (SQLite clone) from scratch in pure Python
Especially the VM part: https://github.com/spandanb/learndb-py/blob/master/learndb/v...
Compare it with this: https://github.com/sqlite/sqlite/blob/master/src/vdbe.c
That's said, I'm curious how complete this LearnDB is. SQLite is hard to read not only it's old but also it covers a lot of SQL and following SQL spec makes hings complicated. SQLite has great test suite so it's nice if you run the suit against this implementation.
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SQLite Begin Concurrent
Correct, see the github mirror[1]. I don't know how well supported that feature is compared to main branch. If it was completely stable, then it would have already landed in the main stable branch. Clarity about the roadmap of that branch would be nice.
- Why sqlite3 temp files were renamed 'etilqs_*' (2006)
- SQLite builds for WASI since 3.41.0
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SQLite VS sqlite_blaster - a user suggested alternative
2 projects | 17 Mar 2023
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Stop Saying “Technical Debt”
Including comprehensive comments, documentation and tests in a codebase takes time and effort.
Failing to do so creates code that is very difficult to maintain or for someone new to the codebase to understand.
However, time and effort may not be what the organization wants to pay for, and individuals may view their own incomprehensible code as something like job security, as they can't be replaced by someone else easily.
As an example of complicated code that's still well-documented, the open-source sqlite code is a good example, about 1/4 of the B-tree file is comments, every time a variable is defined there's a short note explaining what it's used for, every function has a comment header that's comprehensive, such that someone new to the codebase could construct a map of how it all works fairly quickly. It's a good model for how to avoid the problem:
- Ce aplicație v-ar plăcea să o studiați code related?
What are some alternatives?
LevelDB - LevelDB is a fast key-value storage library written at Google that provides an ordered mapping from string keys to string values.
sqlcipher - SQLCipher is a standalone fork of SQLite that adds 256 bit AES encryption of database files and other security features.
LMDB - Read-only mirror of official repo on openldap.org. Issues and pull requests here are ignored. Use OpenLDAP ITS for issues.
SQLite - Unofficial git mirror of SQLite sources (see link for build instructions)
sqlite_orm - ❤️ SQLite ORM light header only library for modern C++
sled - the champagne of beta embedded databases
bolt
ClickHouse - ClickHouse® is a free analytics DBMS for big data
phpMyAdmin - A web interface for MySQL and MariaDB
TileDB - The Universal Storage Engine
Firebird - FB/Java plugin for Firebird