是否可以在Solr中创建一个多值多字段，以允许在查询时使用自定义逻辑？

Question

I'm working with a pretty niche requirement to model a relational structure within Solr and thought that a custom polyfield would be the most suitable solution to my problem. In short, each record in the index will have a number of embargo and expiry dates for when the content should be considered 'available'. These dates are grouped with another kind of categorisation (let's say by device), so for example, any given item in the index may be available for mobile users between two dates, but only available for desktop users between another two dates.

Much like the currency and the latlon types, I would index the values as a comma separated list representing each availability window, for example:

mobile,2013-09-23T00:00:00Z,2013-09-30T00:00:00Z 

So, a single index record could look like

{
    id: "1234",
    text: ["foobarbaz"],
    availability: [
        "mobile,2013-09-23T00:00:00Z,2013-09-30T00:00:00Z",
        "pc,2013-09-22T00:00:00Z,2013-09-30T00:00:00Z"
    ]
}

The custom type would do the job of parsing the incoming value and storing it accordingly. Is this a viable solution? How would I approach the custom logic required at query time to filter by device and then make sure that NOW is within the provided dates?

My attempt so far has been based on the Currency field type, but now I've dialled it back to just storing the string in its un-parsed state. If I could prove that the filtering I want is even possible before using the polyfield features, then I'll know if it's worth continuing.

Does anybody else have any experience writing custom (poly)fields, or doing anything similar to what I'm doing?

Thanks!

Answer 1

If you want to be able to filter and search on these ranges, I don't think you'll have much luck storing records like that. It would make more sense to me to have a more structured document, something like:

id: "1234",
text: ["foobarbaz"],
mobileavailabilitystart: "mobile,2013-09-23T00:00:00Z",
mobileavailabilityend: "2013-09-30T00:00:00Z",
pcavailabilitystart: "2013-09-22T00:00:00Z", 
pcavailabilityend: "2013-09-30T00:00:00Z"

Indexing the full contents of a csv line in Lucene/Solr, in a single field, would allow you to perform full-text searches on it, but would not be a good way to support querying for a specific element of it.