Solr custom wildcard

Question

I am pretty new to Solr and I am looking for a way to port the search features I have for my web application having a regular database to use Solr indexes. My problem so far is I have to customize the wildcards behaviour: for example, "?" should be "0 or 1 characters" not any character as it is now, "+" should mean any "white-space", "#" should be any digit and so on. Any good pointer?

Thanks!

Answer 1

It looks like the best choice in this case is to use regular expressions in the search. More details can be found here: http://1opensourcelover.wordpress.com/2013/09/29/solr-regex-tutorial/

It's not exactly what I was looking for as I will have to build my own solr-query on the back and I have a feeling that regular expressions abuse will create a little bit more overhead on my server. For the test I did it looks pretty fast.

I will leave the question open for a while maybe someone can come up with a better answer.

Answer 2

There is no simple answer that I know of, I am afraid.

For 0 or 1 characters - you can replace the original query with an 'OR' query. Eg. mp? in your db search usecase becomes - 'mp OR mp?' in Solr.

White spaces are tokenized by default in text field. So, you can look at using a white space tokenizer as part of your custom 'text' field. There are several examples. text_ws in the sample schema only does whitespace tokenizing. You'd want to readup on tokenizers.

http://wiki.apache.org/solr/AnalyzersTokenizersTokenFilters

There is no digit equivalent - you can do term1* OR term2* OR term3* ... etc. You can also use function queries that support numerical functions. http://wiki.apache.org/solr/FunctionQuery