Reference

Glossary

A quick reference to Liven terminology, explained without jargon.

Core Concepts Query Language Data Types Operations Deployment Modes Security Terms Storage & Durability Performance Terms Observability Terms Integration Terms

Core Concepts

Term	What it means	Simple analogy
Stream	A collection of related records	Like a folder or a table
Record	A single piece of data with a key and value	Like a row in a spreadsheet
Key	A unique identifier for a record	Like a username or ID number
Value	The actual data stored	Like the content of a file
Pipeline	A series of steps that process data	Like an assembly line
Stage	One step in a pipeline	Like one worker on the line

Query Language

Term	What it means	Example
from()	Pick which stream to read	from("users")
filter()	Keep only matching records	filter(age > 18)
get()	Look up a specific key	get("user_123")
map()	Pick which fields to show	map(name, email)
sort()	Order the results	sort(created_at, desc)
limit()	Return only the first N results	limit(10)
group()	Bundle records by a value	group(city, count())
window()	Group records by time bucket	window(60000, count)
enrich()	Add data from another stream	enrich("profiles", "user_id")
correlate()	Find related events within a time window	correlate("purchases", "user_id", 60000)
chain()	Follow a path across multiple streams	chain("responses", "request_id")
distinct()	Remove duplicates	distinct(email)
listen()	Get live updates after historical results	.listen()
tail()	Watch a stream in real-time	tail("events")

Data Types

Term	What it means	Looks like
Null	Nothing, empty	null
Bool	True or false	true / false
Int	Whole number (positive or negative)	42, -17
UInt	Whole number (positive only)	12345u
Float	Number with decimal	3.14
String	Text	"hello world"
Binary	Raw bytes	0xDEADBEEF
Array	List of values	[1, 2, 3]
Object	Collection of named fields	{"name": "Alice"}
Vector	List of numbers for AI search	[1, -2, 3, 0]

Operations

Term	What it means	Simple analogy
Insert	Add a new record	The key doesn't exist yet
Upsert	Add or overwrite	You don't care if it exists
Update	Modify specific fields	Keep existing data, change some values
Delete	Remove a record	Permanently erase
Empty	Remove all records from a stream	Clear everything
Drop	Delete an entire stream	Remove the stream and all its data

Deployment Modes

Term	What it means	Simple analogy
Embedded	Liven runs inside your application	Edge devices, IoT, desktop apps
Server	Liven runs as a separate process	Production backends, APIs
TUI	Terminal-based interactive shell	Admin tasks, debugging
Web UI	Browser-based dashboard	Visual monitoring, ad-hoc queries

Security Terms

Term	What it means	Simple analogy
Auth Key	A secret password to connect	Like an API key
Role	What a key is allowed to do	Read-only, write-only, or admin
Capabilities	Specific permissions	What actions are allowed
mTLS	Mutual encrypted connection	Both sides prove their identity
Certificate	Digital ID card	Like a passport for servers
Revoke	Cancel access	Turn off a key permanently

Storage & Durability

Term	What it means	Simple analogy
Append-Only	New data goes at the end	Old data never gets overwritten
Segment	A chunk of data on disk	Like a chapter in a book
Compaction	Cleaning up old data	Frees up disk space
CRC32	A checksum to verify data	Catches corruption
Recovery	Restarting after a crash	Your data comes back safely
Tombstone	A marker that a record was deleted	How deletion is tracked

Performance Terms

Term	What it means	Simple analogy
Lock-Free	No waiting in line	Multiple people can read at once
SkipMap	A fast way to find keys	Like an index in a book
Batch Write	Many writes grouped together	Like sending a package vs letters one by one
Index	A shortcut to find data	Like a table of contents
Scan	Reading everything in order	Like reading a book page by page
Point Lookup	Finding one specific record	Like looking up a word in a dictionary

Observability Terms

Term	What it means	Simple analogy
Metrics	Numbers about system health	RAM used, disk space, record counts
Explain	Show how a query will run	Will it be fast or slow?
Status	Current server state	Connections, capacity
Span	A timed operation	How long each part took

Integration Terms

Term	What it means	Simple analogy
TCP	Direct network connection	Fast, low-latency, custom clients
WebSocket	Live two-way connection	Real-time browser apps
REST API	Web-style JSON endpoints for the Web UI	Web UI dashboard
CLI	Command-line interface	Scripts, terminal, automation

Tip: Bookmark this page. When you see a term you don't recognize, come back here.