A developer changes the embedding model used for indexing a document corpus. Which two steps are necessary before trusting the new retrieval configuration? Select 2 answers.

1. Treat the first successful HTTP request as sufficient quality evidence.
2. Validate only that the generator still accepts a prompt string.
3. Recompute or migrate stored embeddings into a representation compatible with the new encoder.
4. Evaluate representative queries against the rebuilt or migrated index.
5. Keep incompatible old vectors because their dimension happens to match.