Option for returning unlimited number of search hits needs to be removed.
While this worked with relational database (Legacy Search Engine), Solr and Elasticsearch were never made to provide for this. Using big number to fake unlimited (1073741824 for Legacy Search Engine) routinely causes OOM exceptions with Solr and Elasticsearch.
Solr and Elasticsearch were made to work with returning relatively small number of hits, providing paging/scrolling for the case when full set is required.
Null as an alias for unlimited in Query objects should be removed, but also other service methods that rely on search should be updated.
Limit should always be expected to be set to a definite number.