H2
CouchDB
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H2 | CouchDB | |
---|---|---|
11 | 27 | |
4,042 | 6,009 | |
1.2% | 0.9% | |
9.1 | 9.5 | |
10 days ago | 7 days ago | |
Java | Erlang | |
GNU General Public License v3.0 or later | MIT License |
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.
H2
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H2 Database – CVE getting flagged by automated scans
The URL should point to a particular comment, but HN removes fragments: https://github.com/h2database/h2database/issues/3686#issueco...
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“Our paying customers need X, when will you fix it?”
This sounds very much like the idiocy of "infosec" lunkheads who know nothing about what they're "fixing" but if an automated system tells them a CVE exists, they've absolutely got to have it "patched". They don't look into what the claims of the CVE are, or whether their specific use case is vulnerable. They don't know, they don't care, they're not even programmers. All they know is a box needs ticking.
A similar thing happened with h2database - a "security researcher" found that if you do something you're told not to do, then bad things happen.. but they demanded and got a CVE allocated anyway. Anyone who looks at it realises it's bullshit, but the mere existence of a CVE is all that matters to these idiots.
What the h2database developer said about it: https://github.com/h2database/h2database/issues/3686#issueco...
> I struggle to understand why I should feel the slightest shred of sympathy for "major corporations" that are using a volunteer-developed open-source project. Feel free to get your corporation to pay someone to deal with this, or pay for a similar commercial library.
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SQLite Internals: How the Most Used Database Works
> ...than it would be to learn the exact syntax and quirks and possibly bugs of someone else's implementation...
Yup. Also, having deep knowledge of the language is required.
SQLite's grammar is neat. Creating a compatible parser would make a fun project. Here's a pretty good example: https://github.com/bkiers/sqlite-parser (Actual ANTLR 4 grammar: https://github.com/bkiers/sqlite-parser/blob/master/src/main... )
Postgres, which tries to be compliant with the latest standards, however...
SQL-2016 is a beast. Not to mention all the dialects.
I'm updating my personal (soon to be FOSS) grammar from ANTLR 3 LL(k) to ANTLR 4 ALL().
I've long had a working knowledge of SQL-92, with some SQL-1999 (eg common table expressions).
But the new structures and extensions are a bit overwhelming.
Fortunately, ANTLR project has ~dozen FOSS grammars to learn from. https://github.com/antlr/grammars-v4/tree/master/sql
They mostly mechanically translate BNFs to LL(k) with some ALL(). Meaning few take advantage of left-recursion. https://github.com/antlr/antlr4/blob/master/doc/left-recursi...
Honestly, I struggled to understand these grammars. Plus, not being conversant with the SQL-2016 was a huge impediment. Just finding a succinct corbis of test cases was a huge hurdle for me.
Fortunately, the H2 Database project is a great resource. https://github.com/h2database/h2database/tree/master/h2/src/...
Now for the exciting conclusion...
My ANTLR grammar which passes all of H2's tests looks nothing like any of the official or product specific BNFs.
Further, I found discrepancy between the product specific BNFs and their implementations.
So a lot of trial & error is required for a "real world" parser. Which would explain why the professional SQL parsing tools charge money.
I still think creating a parser for SQLite is a great project.
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Database of Databases
H2 - Free, Embedded & Open source
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🎀 Spring Boot 2.7.0 Released
H2 2.1
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How is the market for Kotlin developers where you live?
H2 for mocking relational database connections
- Ask HN: Who wants to be hired? (December 2021)
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Best Database option for a Swing application
It's open-source and written in Java, so you can even create custom procedures and register them straight in your application!
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Reliable WebSockets-based pub/sub with Spring Boot
Firstly, let's set up a basic Spring Boot application. We can use the Spring Initializr with Spring Data JPA, H2 Database, Lombok added. H2 Database will provide us with a simple database, and Spring Data JPA will allow us to easily interact with it using Hibernate. Lombok will make it easier to write concise and readable classes.
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Why are tar.xz files 15x smaller when using Python's tar compared to macOS tar?
Sorting chunks by similarity: commonly used tools don't do that. Most archive tools only sort by file type.
I wrote a tool that chunks the data (into variable-sized blocks, to re-sync if there are multiple files that have different length prefixes, but that's another story), and then sorts the chunks by LSH (locality sensitive hash). LSH is used by search engines to detect similar text. It can compress directories that contain multiple version of e.g. source code very well (e.g. trunk, branches). https://github.com/h2database/h2database/blob/master/h2/src/...
I discussed this approach with a researcher in this area in January 2020. AFAIK there is active research in this area, specially to compress DNA sequences. But he also wasn't aware of papers or research in this area for general-purpose data compression.
So, I think this area is largely uncharted. I would be interested (as a hobby side project) to help, if somebody is interested.
CouchDB
- Why SQLite is so great for the edge
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Creating an offline node.js app, but what can I use as a database?
CouchDB is a json based database for simple projects. The fork pouchdb offers lots of support for offline.
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How to run WebAssembly from your Rust Program
Apache CouchDB belongs to the family of NoSQL databases. It is a document store with a strong focus on replication and reliability. One of the most significant differences between CouchDB and a relational database (besides the absence of tables and schemas) is how you query data. Relational databases allow their users to execute arbitrary and dynamic queries via SQL. Each SQL query may look completely different than the previous one. These dynamic aspects are significant for use cases where you work exploratively with your dataset but don't matter as much in a web context. Additionally, defining an index for a specific table is optional. Most developers will define indices to boost performance, but the database does not require it.
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Erlang: The coding language that finance forgot
I just turns out you can't always do that in a real codebase. For example see here:
https://github.com/apache/couchdb/blob/23efd8e5b1aa96ef01640fec03a5fedc945ba8b9/src/couch_mrview/src/couch_mrview_http.erl#L228
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System Design: The complete course
Example: Apache Cassandra, CouchDB.
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Help need for Third Year Computer Science Project which is a dating website.
For non-SQL-based databases, consider MongoDB, or CouchDB, which are very easy to get started with.
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PDF Reviewer (3) - The Architecture
The Apache CouchDB server. It stores Annotation data.
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Database of Databases
CouchDB
- [AskJS] technology stack for PWA, ServiceWorker and offline first web app?
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How would you implement online offline db sync?
You can implement the sync algorithm from scratch, or you can use tools like CouchDB and turtleDB to help you.
What are some alternatives?
MapDB - MapDB provides concurrent Maps, Sets and Queues backed by disk storage or off-heap-memory. It is a fast and easy to use embedded Java database engine.
Riak - Riak is a decentralized datastore from Basho Technologies.
HikariCP - 光 HikariCP・A solid, high-performance, JDBC connection pool at last.
LevelDB - LevelDB is a fast key-value storage library written at Google that provides an ordered mapping from string keys to string values.
MariaDB4j - MariaDB Embedded in Java JAR
RethinkDB - The open-source database for the realtime web.
Flyway - Flyway by Redgate • Database Migrations Made Easy.
Redis - Redis is an in-memory database that persists on disk. The data model is key-value, but many different kind of values are supported: Strings, Lists, Sets, Sorted Sets, Hashes, Streams, HyperLogLogs, Bitmaps.
JetBrains Xodus - Transactional schema-less embedded database used by JetBrains YouTrack and JetBrains Hub.
Apache Cassandra - Mirror of Apache Cassandra
Chronicle Map - Replicate your Key Value Store across your network, with consistency, persistance and performance.
Appwrite - Build like a team of hundreds_