Detailed Explanation: A semantic-search schema should use the pgvector vector type for embeddings so PostgreSQL can apply vector distance operators and vector indexes. The creation timestamp should use an actual timestamp data type so comparisons, range predicates, ordering, and indexes use date semantics rather than string ordering. Storing vectors or dates as free-form character data would sacrifice type validation and make similarity or date filtering less efficient and less reliable.
Study Guide Alignment: AI data-management workloads: Cosmos DB, PostgreSQL, caching, vector storage, vector retrieval, consistency, and connection optimization.
Official Microsoft Learn References: AI-200 Study Guide | Vector similarity search with Azure PostgreSQL