I have two texts:
Text-1
Our new Android Smartphone
Text-2
Our new iPhone Smartphone
I would like to tell Solr that "android" is a "smartphone".
Expected results:
If the user searches for "Android" only the first text should be found.
If the user searches for "Smartphone" both texts should be found.
If I use "equal synonyms" (SolrSynonymParser) (during indexing), then the term "Smartphone" would get expanded to "Smartphone, Android, iPhone" in both texts.
In addition to the comment of MatsLindh, to add an unidirectional synonym like: "android=>android,smartphone", you should also consider to add the Synonym Filter only at index time and not both at index and query time
For example:
<analyzer type="index">
...
<filter class="solr.SynonymGraphFilterFactory" synonyms="synonyms.txt"/>
...
</analyzer>
This way, both "android" and "smartphone" will be indexed for any occurrence of "android"