As we saw in the previous recipe, the index partition is associated with a property database. As your site grows and the items in the index grow, metadata needs become a possible bottleneck.
This information is stored in the property database. If users are performing many metadata searches, then more property databases (either on the same or separate SQL Servers) may need to be added to relieve this congestion. This recipe shows how to achieve this.
You must have farm-level administrative permissions to the Central Administration site.