Query examples using Parquet - Neptune Analytics

Query examples using Parquet

The following example query returns the number of rows in a given Parquet file: 

CALL neptune.read(
  {
    source: "<s3 path>",
    format: "parquet"
  }
)
YIELD row
RETURN count(row)

You can run the query example using the execute-query operation in the AWS CLI by executing the following code: 

aws neptune-graph execute-query \
  --graph-identifier ${graphIdentifier} \
  --query-string 'CALL neptune.read({source: "<s3 path>", 
    format: "parquet"}) YIELD row RETURN count(row)' \
  --language open_cypher \
  /tmp/out.txt

A query can be flexible in what it does with rows read from a Parquet file. For example, the following query creates a node with a field being set to data found in the Parquet file: 

CALL neptune.read(
  {
    source: "<s3 path>",
    format: "parquet"
  }
)
YIELD row
CREATE (n {someField: row.someCol}) 
RETURN n
Warning

It is not considered good practice to use a large results-producing clause like MATCH(n) prior to a CALL clause. This would lead to a long-running query, due to cross product between incoming solutions from prior clauses and the rows read by neptune.read. It’s recommended to start the query with CALL neptune.read.