Importing massive dataset in Neo4j where each entity has differing properties - csv

Question

I'm trying to bulk load a massive dataset into a single Neo4j instance. Each node will represent a general Entity which will have specific properties, e.g.:
label
description
date
In addition to these there are zero or more properties specific to the Entity type, so for example if the Entity is a Book, the properties will look something like this:
label
description
date
author
first published
...
And if the Entity is a Car the properties will look something like this:
label
description
date
make
model
...
I first attempted to import the dataset by streaming each Entity from the filesystem and using Cypher to insert each node (some 200M entities and 400M relationships). This was far too slow (as I had expected but worth a try).
I've therefore made use of the bulk import tool neo4j-admin import which works over a CSV file which has specified headers for each property. The problem I'm having is that I don't see a way to add the additional properties specific to each Entity. The only solution I can think of is to include a CSV column for every possible property expressed across the set of entities, however I believe I will end up with a bunch of redundant properties on all my entities.
EDIT1
Each Entity is unique, so there will be some 1M+ types (labels in Neo4j)
Any suggestions on how to accomplish this would be appreciated.

Answer 1

The import command of neo4j-admin supports importing from multiple node and relationship files.
Therefore, to support multiple "types" of nodes (called labels in neo4j), you can split your original CSV file into separate files, one for each Entity "type". Each file can then have data columns specific to that type.
[UPDATED]
Here is one way to support the import of nodes having arbitrary schemata from a CSV file.
The CSV file should not have a header.
Every property on a CSV line should be represented by an adjacent pair of values: 1 for the property name, and 1 for the property value.
With such a CSV file, this code (which takes advantage of the APOC function apoc.map.fromValues) should work:
LOAD CSV FROM "file:///mydata.csv" AS line
CREATE (e:Entity)
SET e = apoc.map.fromValues(line);
NOTE: the above code would use strings for all values. If you want some property values to be integers, booleans, etc., then you can do something like this instead (but this is probably only sensible if the same property occurs frequently; if the property does not exist on a line no property will be created in the node, but it will waste some time):
LOAD CSV FROM "file:///mydata.csv" AS line
WITH apoc.map.fromValues(line) AS data
WITH apoc.map.setKey(data, 'foo', TOINTEGER(data.foo)) AS data
CREATE (e:Entity)
SET e = apoc.map.fromValues(line);