There is no widely-agreed upon definition of service-oriented architecture other than its literal translation that it is an architecture that relies on service-orientation as its fundamental design principle. Service-orientation describes an architecture that uses loosely coupled services to support the requirements of business processes and users. Resources on a network in an SOA environment are made available as independent services that can be accessed without knowledge of their underlying platform implementation. These concepts can be applied to business, software and other types of producer/consumer systems.
Search oriented architecture
The use of search engine technology as the main integration component in an information system. In a traditional business environment the architectural layer usually occupied by a relational database management system(RDBMS) is supplemented or replaced with a search engine or the indexing technology used to build such engines. Queries for information which would usually be performed using Structured Query Language(SQL) are replaced by keyword or fielded(or field-enabled) searches for structured, semi-structured, or unstructured data.
In a typical multi-tier or N tier architecture information is maintained in a Data-Tier where it can be stored and retrieved from a database or file system. The data tier is queried by the logic or business tier when information is needed using a data retrieval language like SQL.
This is why I try to stay away from acronyms and am very careful in my use of terminoloy.