Frequently Asked Questions

Liven is a database that unifies streaming, processing, and storage in one engine. It handles real-time data ingestion, on-the-fly transformations, and durable storage — all with a single query language.

One command:

curl -fsSL https://livendb.com/install | sh

Or Docker:

docker run -p 43121:43121 -p 43120:43120 ghcr.io/livendb/liven

No. Liven is a single binary with no runtime dependencies.

A stream is a collection of key-value records, similar to a table. Streams are created automatically when you first write to them.

from("orders") | filter(amount > 100) | count()

Yes. Liven runs as a Rust library:

let db = Liven::open("./data")?;
db.query(r#"from("events").insert("k1", {value: 42})"#)?;

Yes. Run `liven start` to start the server on port 43121 (database protocol) and 43120 (web UI).

Point lookups complete in microseconds. Writes are batched for high throughput — thousands of writes per second on modest hardware.

No. The index stores only keys and pointers, not full records. Index size is typically 1-2% of your data size. You can set a RAM limit (default 16 MB).

Yes. The index is lock-free, allowing thousands of simultaneous reads. Writes run on a dedicated thread and never block reads.

Liven's append-only design means existing data is never overwritten. On recovery, incomplete writes are discarded. Your data remains intact.

Yes. Every record includes a CRC32 checksum. Corruption is detected immediately on every read.

Liven detects disk full errors and returns a clear error. Your application can handle it gracefully.

Yes. Two modes:

• Auth-key mode: Symmetric keys with roles (read, write, admin). Keys can be revoked at runtime.
• None mode: No authentication (development only).

• Read-only: Query and subscribe
• Write-only: Insert and update
• Admin: Drop streams and trigger compaction

Run the status() query:

status()

Or use the web dashboard at http://localhost:43120.

Use explain():

explain("from(events) | filter(timestamp > 1704067200)")

Liven is self-managing. Compaction runs automatically in the background.

• Rust: Native embedding via the liven crate
• Any language: Native TCP protocol or WebSocket

Yes:

liven start           # Start the server
liven stop            # Stop the server
liven query "..."     # Run a query
liven tail "stream"   # Watch a stream in real-time
liven vibe            # Interactive TUI shell

1. Run explain("your query") to see the plan
2. Add a timestamp filter to avoid full scans
3. Use limit(N) to restrict results

Liven uses ports 43121 (database) and 43120 (web UI). Stop the existing instance:

liven stop

Yes. Liven is open source under the Apache License, Version 2.0. It is free for any use, including commercial and proprietary embedding.

• GitHub Issues: github.com/livendb/liven/issues
• Email: team@livendb.com (commercial inquiries)