Hi Maksimov,
A key consideration here is how many of the dozens of properties do you intend to be searchable? Alfresco stores data in 3 key areas: The content store (filesystem) for the physical content (e.g. document itself), the Alfresco database for the metadata associated with the content (including properties, associations, workflow instances/details/history, audit information, users, groups, ACLs) and lastly Alfresco uses Apache Solr for indexing the content and any searchable metadata and associated permissions (in Lucene indexes also on the file system)
The sizing of the indexing elements (ensuring Solr has enough resources/CPU/RAM etc) are just as key to fast performance as the tuning of the database and the Alfresco repository
Regards
Steven