String search by prefix

[Andreas Jung]

As part of a CMS migration we store all content as JSON in ArangoDB. Content objects have to path properties

_path = '/path/to/my/content/foo.html'

_path2 = ['path', 'to', 'my', 'content', 'foo.html']

Basic question: what is the best way to query in AQL for all documents by where _path matches a particular prefix like '/path' or '/path/to/my/content'.

I can use FILTER doc._path like '/path/%' but that's not very efficient...any better idea?

[Wilfried Gösgens]

Hi,

maybe adding a 3rd attribute that has a part of the path, which is pretty distinguishable but can be indexed with a good selectivity and used to compare in AQL with `==`is a good addition performance wise?

So you would use the `==` to reduce the result set perfomant with the help of the index, and afterwards filter the reduced result set by the left bound string match.

Cheers,

Willi

[Andreas Jung]

SOLVED

For each document I pre-compute an array of possible prefixes and store it as attribute _all_paths - in this case:

doc._all_paths = [

'/path',

'/path/to',

'/path/to/my',

'/path/to/my/content'

]

Then I can query this field using the IN operator:

for doc in mycollection

    FILTER '/some/path' in doc._all_paths

Andreas

On Wednesday, May 15, 2019 at 11:59:18 AM UTC+2, Andreas Jung wrote: