Sphinx config wildcard searching

[Gnuru]

I want to share my sphinx.config for enhancing the search system to enable wildcard searching. E.g. if you search for "inv" search results also displays "invision" etc.

index ips
{
        type                    = rt
        path                    = /var/lib/sphinxsearch/index
        rt_field                = index_title
        rt_field                = index_content
        rt_field                = index_tags
        rt_attr_bigint          = index_object_id
        rt_attr_bigint          = index_item_id
        rt_attr_bigint          = index_container_id
        rt_attr_bigint          = index_author
        rt_attr_bigint          = index_views
        rt_attr_bigint          = index_num_comments
        rt_attr_bigint          = index_num_reviews
        rt_attr_json            = index_permissions
        rt_attr_timestamp       = index_date_created
        rt_attr_timestamp       = index_date_updated
        rt_attr_string          = index_class
        rt_attr_uint            = index_class_id
        rt_attr_uint            = index_hidden
        index_exact_words       = 1
        enable_star             = 1
        min_prefix_len          = 3
        expand_keywords         = 1
        html_strip              = 1
        morphology              = soundex, metaphone
        wordforms               = /var/lib/sphinxsearch/wordforms.txt
}