Neo4j.Stream (Neo4jEx v0.1.4)
View SourceStreaming interface for large Neo4j result sets.
This module provides a way to process large result sets without loading all data into memory at once. It uses Elixir's Stream.resource/3 to create a stream that fetches data in batches using Neo4j's SKIP/LIMIT pagination.
Summary
Functions
Creates a stream for large result sets.
Parameters
- driver: Driver process
- query: Cypher query string
- params: Query parameters map (default: %{})
- opts: Query options (default: [])
Options
:batch_size- Number of records to fetch at once (default: 1000):timeout- Query timeout in milliseconds (default: 30000)
Returns
Stream of records
Examples
# Basic streaming
driver
|> Neo4j.Stream.run("MATCH (n:Person) RETURN n")
|> Stream.map(fn record -> process_person(record) end)
|> Stream.run()
# With custom batch size
driver
|> Neo4j.Stream.run("MATCH (n:BigData) RETURN n", %{}, batch_size: 500)
|> Stream.chunk_every(100)
|> Enum.each(&batch_process/1)
# Memory-efficient aggregation
total = driver
|> Neo4j.Stream.run("MATCH (n:Transaction) RETURN n.amount")
|> Stream.map(fn record -> record |> get_field("n.amount") end)
|> Enum.sum()Stream with custom processing function.
Parameters
- driver: Driver process
- query: Cypher query string
- params: Query parameters map (default: %{})
- processor_fn: Function to process each record
- opts: Query options (default: [])
Options
:batch_size- Number of records to fetch at once (default: 1000):timeout- Query timeout in milliseconds (default: 30000)
Returns
Stream of processed records