Free DP-800 Questions Attempt

The correct way to avoid full table scans here is to add a computed column that extracts the JSON scalar property with JSON_VALUE , and then create a nonclustered index on that computed column with the report’s returned columns in the INCLUDE list. Microsoft’s JSON indexing guidance specifically recommends creating a computed column that exposes the JSON property you filter on, using the same expression as in the query, and then indexing that computed column.

So the computed column must be:

AS JSON_VALUE([log], ' $.severity ' ) PERSISTED

This is correct because $.severity is a scalar JSON value, so JSON_VALUE is the proper function. JSON_QUERY would be for extracting an object or array, not a scalar property. Microsoft also notes that persisted computed columns can improve access speed for JSON-derived values.

The index should then include:

INCLUDE (LogId, LogDateTime, [log])

That is the right covering strategy because the report filters by severity but returns LogId, LogDateTime, and log. Microsoft’s guidance on included columns explains that nonkey included columns let a nonclustered index cover more queries and reduce extra lookups to the base table.

So the completed code is:

ALTER TABLE WebSite.Logs

ADD severity AS JSON_VALUE([log], ' $.severity ' ) PERSISTED;

GO

CREATE INDEX ix_severity

ON WebSite.Logs(severity)

INCLUDE (LogId, LogDateTime, [log]);

GO

When you change embedding models, the stored vectors should be treated as belonging to a different embedding space unless you intentionally keep the entire corpus consistent. Microsoft’s vector guidance notes that when most or all embeddings are replaced with fresh embeddings from a new model, the recommended practice is to reload the new embeddings and, for large-scale replacement scenarios, consider dropping and recreating the vector index afterward so search quality remains predictable.

This question also says applications must continue to use VECTOR_SEARCH without runtime errors . VECTOR_SEARCH requires compatible vector dimensions, and the vector column already exists. Azure OpenAI documentation shows that text-embedding-ada-002 is fixed at 1536 dimensions and text-embedding-3-small supports up to 1536 dimensions . That means the migration can remain compatible with a VECTOR(1536) column, but the right implementation step is still to re-embed the existing rows so the table does not contain a mixed corpus produced by different models.

The other options are not appropriate:

B normalization does not solve a model migration problem.

C converting the vector column to nvarchar(max) would break vector-native search design.

D a vector index improves performance, but it does not migrate old embeddings to the new model.