TL;DR; You can even start with a single node, but you loose the highly available factor of c*. Cassandra is built for systems that handle huge volumes of data, terabytes and in some cases petabytes. Many users typically switch from MySQL (and lots of other RDBMS) to Cassandra once they find that their current DB … Read more
For a 1D numpy array, you can use lists: # serialize 1D array x record[‘feature1’] = x.tolist() # deserialize 1D array x x = np.fromiter( record[‘feature1′] ) For multidimensional data, I believe you’ll need to use pickle and pymongo.binary.Binary: # serialize 2D array y record[‘feature2’] = pymongo.binary.Binary( pickle.dumps( y, protocol=2) ) ) # deserialize 2D … Read more
You can just do: db.collection.distinct(“children.child_name”); In your case it returns: [ “John”, “Anna”, “Kevin” ]
@Joni is correct, you need to use datetime. from datetime import datetime from pymongo import Connection # i have updated and included the complete code client = Connection(‘localhost’, 27017) db = client[‘database’] # your database name inoshare = db[‘inoshare’] # convert your date string to datetime object start = datetime(2014, 9, 24, 7, 51, 04) … Read more
Not a direct answer but some pointers to very interesting and somehow similar questions (yeah, they are about blobs and images but this is IMO comparable). What are the downsides of storing files as BLOBs in MySQL? Storing Images in DB – Yea or Nay? Images in database vs file system https://stackoverflow.com/search?q=images+database+filesystem Do the same … Read more
MongoDB stores data in a binary format called BSON which supports these numeric data types: int32 – 4 bytes (32-bit signed integer) int64 – 8 bytes (64-bit signed integer) double – 8 bytes (64-bit IEEE 754 floating point) There’s no exact value fixed-point equivalent to mySQL’s decimal type in MongoDB, but you can store 64-bit … Read more
Man, I had a similar issue creating an Schema like this: QuestionnaireSchema = mongoose.Schema({ formId: Number, name: String, questions: [ { type: String, title: String, alternatives:[{ label: String, value: “Mixed” }] } ] }); My mistake was that I am using “type” as a field name and this is reserved word in mongoose. I just … Read more
Assuming you’re referring to Neo4j’s internal node id: MATCH (p:Person) where ID(p)=1 OPTIONAL MATCH (p)-[r]-() //drops p’s relations DELETE r,p If you’re referring to your own property ‘id’ on the node: MATCH (p:Person {id:1}) OPTIONAL MATCH (p)-[r]-() //drops p’s relations DELETE r,p