RavenDB model questions - database

Question

I'm considering using RavenDb for a new project we're doing at our company.
The project will consist of entities that have a set of dynamic properties based on the labels that a user might attach to them.
Example:
Entity called Image has:
Id
Name
Size
We want to use Labels (just another entity in the system) to allow the users to create specific properties for an image.
A label consists of a name, and might have a parent label.
If the user creates two Labels:
House
Car
The House label has the following properties:
Location
Color
Size
The Car label has the following properties:
Brand
Color
Engine type
Total doors
(These labels and properties must be managed by the user with special edit screens in our application).
When a user then creates an Image and assigns a specific label to that image, all the properties from that label must be present on the new image.
There can be multiple Labels attached to one Image. The Labels should be queried separately in order to show them in the GUI.
My question is:
I know how to do this in SQL. But I'm a bit concerned about the performance when there might be 300000 images with all kinds of properties. Especially when we want to search for those properties.
Can anyone give me a jump start (or an already existing tutorial) for this kind of setup? I'm not sure on how to model my entities for this kind of data.
Thnx!

Answer 1

Not quite sure what you mean by "Labels should be queried separately in order to show them in the GUI." but a document for each image with the properties from each label stored directly would be a starting point.
E.g.
public class Image
{
public string Id { get; set; }
public string Name { get; set; }
public Dictionary<string, Dictionary<string, object>> LabelProperties { get; set; }
}
You can then populate this as follows:
var img1 = new Image
{
Name = "Image1",
LabelProperties = new Dictionary<string, Dictionary<string, object>>
{
{
"Car",
new Dictionary<string, object>
{
{ "Brand", "GM"},
{ "Color", "Blue"},
{ "Engine type", "Big"},
{ "Total doors", 4}
}
},
{
"House",
new Dictionary<string, object>
{
{ "Location", "Downtown"},
{ "Color", "Blue"},
{ "Size", 240}
}
}
}
};
This then ends up looking quite nicely structure JSON in the db:
{
"Name": "Image1",
"LabelProperties": {
"Car": {
"Brand": "GM",
"Color": "Blue",
"Engine type": "Big",
"Total doors": 4
},
"House": {
"Location": "Downtown",
"Color": "Blue",
"Size": 240
}
}
}
You could then query this using dynamic indexes. E.g. to find all images that contain a blue house:
var blueHouses = session.Query<Image>()
.Customize(x => x.WaitForNonStaleResults())
.Where(x => Equals(x.LabelProperties["House"]["Color"], "Blue"));
Console.WriteLine("--- All Images Containing a House of Color Blue");
foreach (var item in blueHouses)
{
Console.WriteLine("{0} | {1}", item.Id, item.Name);
}
If you want to query on the labels themselves an index might be required. See the gist for the full example.