Practice Free DP-800 Developing AI-Enabled Database Solutions Exam Questions Answers With Explanation

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

The correct insertion at line 22 is FOR JSON PATH, WITHOUT_ARRAY_WRAPPER .

The request body for the Azure OpenAI chat completions call must be a single JSON object containing the messages array with both the system/user content and the retrieved chunks. Microsoft documents that FOR JSON PATH is the preferred way to shape JSON output, especially when you want precise control over nested property names like messages[0].role and messages[1] .content.

The key detail is WITHOUT_ARRAY_WRAPPER . By default, FOR JSON returns results enclosed in square brackets as a JSON array. Microsoft documents that WITHOUT_ARRAY_WRAPPER removes those brackets so a single JSON object is produced instead. That is exactly what is needed here for @payload, because the stored procedure is building one request body, not an array of request bodies.

For an SDK-style SQL database project targeting Azure SQL Database , Microsoft recommends using the Azure SQL system DACPAC as a NuGet package reference rather than adding a direct artifact reference to master.dacpac for new SDK-style development. Microsoft’s SQL Database Projects documentation says direct .dacpac artifact references are not recommended for new development in SDK-style projects ; instead, use NuGet package references .

Because the goal is specifically to make dotnet build validate successfully with the correct Azure SQL system objects , adding an artifact reference to master.dacpac is not the recommended SDK-style solution. It can work in some project styles, but it does not meet the stated goal as the proper approach for SDK-style Azure SQL projects.

Microsoft documents REGEXP_SUBSTR for Transact-SQL with the string_expression parameter as supporting character string types char, nchar, varchar, and nvarchar. For the regex functions, support for LOB types such as varchar(max) and nvarchar(max) is specifically called out for REGEXP_LIKE , REGEXP_COUNT , and REGEXP_INSTR up to 2 MB, but that support note is not listed for REGEXP_SUBSTR in the surfaced documentation. In exam terms, the safe and expected approach is to cast the nvarchar(max) column to nvarchar(4000) before calling REGEXP_SUBSTR.

This also fits the scenario detail that the ID is always contained within the first paragraph of MessageText. Since the needed value is near the start of the text, narrowing the input to a non-LOB string type such as nvarchar(4000) is sufficient and avoids incompatibility concerns with nvarchar(max).

The other options are not appropriate:

A STRING_ESCAPE(..., ' json ' ) is for JSON escaping, not regex extraction.

C adding a case-sensitive collation changes comparison behavior, but it is not the required fix for REGEXP_SUBSTR on nvarchar(max).

D TRY_CONVERT(varchar(max), ...) still leaves a MAX type and also risks unnecessary Unicode loss.

The correct answer is D because the requirement is to enable similarity search over embedding vectors and to minimize latency . Microsoft documents that CREATE VECTOR INDEX is specifically used to create an index on vector data for approximate nearest neighbor (ANN) search , which is designed to accelerate vector similarity queries compared to exact k-nearest-neighbor scans.

This matches the scenario exactly. The VehicleHealthSummary table already includes an Embeddings (vector(1536)) column. In Microsoft SQL platforms, embeddings are stored in vector columns and queried for semantic similarity. To improve performance and reduce response time, Microsoft recommends a vector index , not a regular B-tree nonclustered index and not a full-text index. A vector index is purpose-built for finding the most similar vectors efficiently.

The other options are not appropriate:

A would require manual comparison logic and would increase latency rather than minimize it.

B is incorrect because a standard nonclustered index is not the index type used for vector similarity operations.

C is incorrect because full-text indexes are for textual token-based search, not numeric vector embeddings.

Microsoft’s current documentation is explicit that vector indexes support approximate nearest neighbor search , and that the optimizer can use the ANN index automatically for vector queries. That is the exam-aligned design choice when the goal is fast retrieval of the most relevant health summary reports from an embeddings column.

This also does not meet the goal. DROP PARTITION SCHEME removes the partition scheme object from the database; it is not the command used to remove just the rows for the oldest month from a partitioned table. Microsoft’s DROP PARTITION SCHEME documentation is explicit that the statement removes the partition scheme itself.

For removing only the oldest month’s rows with minimal impact, Microsoft points to partition-level maintenance operations such as truncating a single partition on a partitioned table. That targets only the needed data subset and is more efficient for retention workloads.

The first statement is No . The requirement says telemetry data must be stored in a partitioned table to provide predictable performance for ingestion and retention operations. However, the shown CREATE TABLE statement does not define a partition function or partition scheme, and the table is created with a regular clustered primary key on TelemetryId. Microsoft’s partitioning guidance states that creating a partitioned table requires a partition function , a partition scheme , and creating the table or index on that partition scheme using a partitioning column. None of that appears in the code, so the table is not partitioned.

The second statement is Yes . The code creates a JSON index named JI_VehicleTelemetry_Location on LocationJson for these specific JSON paths: $.location.latitude, $.location.longitude, and $.location.accuracy. That matches the requirement that those JSON properties must be filterable by using an index seek . Microsoft documents that JSON indexing is used to optimize filtering and sorting on JSON properties, and the index only helps for the properties included in the index definition.

The third statement is No . The JSON index is defined only for latitude, longitude, and accuracy. A query filtering on $.location.heading references a different path that is not included in the index definition, so that query would not use JI_VehicleTelemetry_Location for that predicate. JSON indexes are path-specific; they do not automatically cover unrelated properties in the same JSON document.

JSON_VALUE(f.FeedbackJson, ' $.text ' ) AS FeedbackText

CONTAINS(FeedbackJson, @Keyword)

SimilarityScore

These three selections are the correct way to complete the query because they align exactly with the stated requirements for the FeedbackJson column.

First, to extract the customer feedback text from the JSON document , the correct expression is JSON_VALUE(f.FeedbackJson, ' $.text ' ) AS FeedbackText . Microsoft documents that JSON_VALUE is used to extract a scalar value from JSON, while JSON_QUERY is used for returning an object or array . Since $.text is the textual feedback string, JSON_VALUE is the correct function.

Second, to filter rows where the JSON text contains a keyword , the best choice is CONTAINS(FeedbackJson, @Keyword) . The scenario explicitly states that FeedbackJson already has a full-text index , and Microsoft documents that CONTAINS is the full-text predicate used in the WHERE clause to search full-text indexed character data. That makes it more appropriate than using EDIT_DISTANCE for keyword filtering.

Third, to order the results by similarity score, highest first , the correct item is SimilarityScore in the ORDER BY clause, which would be paired with DESC in the query. This matches the requirement to sort by the computed fuzzy similarity value. The DP-800 study guide specifically includes writing queries that use fuzzy string matching functions such as EDIT_DISTANCE, which supports the earlier computed SimilarityScore expression in the query.

The schema meets the security requirements for PII data. ? Yes

Administrators of the Azure SQL server can see all the rows in dbo.CustomerProfiles when they use an application. ? No

The masking rules will apply even when row-level security (RLS) filters out rows. ? No

The first statement is Yes because the design combines two relevant SQL security controls for personally identifiable information: Dynamic Data Masking (DDM) on sensitive columns such as FullName, EmailAddress, and PhoneNumber, and Row-Level Security (RLS) to restrict which rows a user can access based on RegionCode. Microsoft documents that DDM limits sensitive data exposure for nonprivileged users , while RLS restricts row access according to the user executing the query. Together, these are valid and appropriate controls for protecting PII in Azure SQL Database.

The second statement is No . Administrative users can view unmasked data because administrative roles effectively have CONTROL, which includes UNMASK. However, that does not mean they automatically see all rows through the application query path defined by the RLS policy. The security policy filters rows based on SUSER_SNAME() and matching RegionCode, so row visibility is governed by the predicate unless the policy is altered or bypassed administratively. DDM and RLS solve different problems: DDM affects how returned values are shown, while RLS affects which rows are returned at all.

The third statement is No because masking only applies to data that is actually returned in the query result set. Microsoft describes DDM as hiding sensitive data in the result set of a query . If RLS filters a row out, that row is not returned, so there is nothing left for masking to act on. In other words, RLS eliminates inaccessible rows first from the user’s perspective, and DDM masks sensitive column values only on rows the user is allowed to see.

The best recommendation is B because the slow query filters on FleetId and returns LastUpdatedUtc , EngineStatus , and BatteryHealth . A nonclustered index with FleetId as the key column allows the optimizer to perform an index seek instead of a clustered index scan, and including the other selected columns makes the index covering , which reduces extra lookups and I/O. Microsoft’s SQL Server indexing guidance states that a nonclustered index with included columns can significantly improve performance when all query columns are available in the index, because the optimizer can satisfy the query directly from the index.

The query is:

SELECT VehicleId, LastUpdatedUtc, EngineStatus, BatteryHealth

FROM dbo.VehicleHealthSummary

WHERE FleetId = @FleetId

ORDER BY LastUpdatedUtc DESC;

Among the given choices, FleetId is the most important search argument because it appears in the WHERE predicate. Microsoft’s index design guidance recommends putting columns used for searching in the key and using nonkey included columns to cover the rest of the query efficiently.

Why the other options are weaker:

A is not appropriate because changing the clustered index to LastUpdatedUtc would not target the main filter predicate on FleetId, and a table can have only one clustered index.

C makes LastUpdatedUtc the key, which is poor for a query whose primary filter is FleetId.

D is not the right answer here because the query requirement does not specify only recent rows, and filtered indexes are meant for a well-defined subset; this option also uses a time-based expression that is not aligned to the stated query pattern.

Strictly speaking, the most optimal design for both filtering and ordering would usually be a composite key like (FleetId, LastUpdatedUtc), but since that is not one of the available options, B is the correct exam answer.

ON ? m.maintenanceId = i.maintenanceId

WHERE ? m.LastModifiedUtc < > i.LastModifiedUtc

The correct drag-and-drop completion is:

ON m.maintenanceId = i.maintenanceId

WHERE m.LastModifiedUtc < > i.LastModifiedUtc

This satisfies the requirement to ensure that when a row in MaintenanceEvents changes, the corresponding LastModifiedUtc value is updated to the current system time, while also helping avoid unnecessary repeat updates.

The inserted pseudo-table in a SQL Server AFTER UPDATE trigger contains the rows that were just updated. To update the matching row in the base table correctly, the trigger must join the target table row to the corresponding row in inserted by the table’s primary key. In this schema, MaintenanceId is the primary key for MaintenanceEvents, so the correct join is m.maintenanceId = i.maintenanceId . Joining on VehicleId would be incorrect because multiple maintenance rows could exist for the same vehicle, which could update unintended rows. Microsoft’s trigger documentation explains that inserted and deleted are used to work with the affected rows and that multi-row logic should be based on proper key matching.

The WHERE m.LastModifiedUtc < > i.LastModifiedUtc predicate is used to prevent the trigger from re-updating rows where the timestamp already matches the value in inserted. That reduces redundant writes and supports the requirement to avoid recursive or repeated update behavior. In practice, this means the trigger updates only rows whose current stored timestamp differs from the just-updated version. This is the exam-appropriate pattern for a self-updating timestamp column in an AFTER UPDATE trigger.

where exists 2. where p.PatientID = pr.PatientID Otherwise we filter PatientID twice. Having in the subquery does not work without group by and the date filter does not work without where.

The two correct actions are D and E because the ingestion failures are caused by malformed JSON and duplicate payloads , and these two controls address those two problems directly. Microsoft’s JSON documentation states that SQL Server and Azure SQL support validating JSON with ISJSON , and Microsoft specifically recommends using a CHECK constraint to ensure JSON text stored in a column is properly formatted.

For the duplicate-payload issue, creating a unique index on a hash of the payload is the appropriate design. Microsoft documents using hashing functions such as HASHBYTES to hash column values, and SQL Server allows a deterministic computed column to be used as a key column in a UNIQUE constraint or unique index . That makes a persisted hash-based computed column plus a unique index a practical and exam-consistent way to reject duplicate payloads efficiently.

The other options do not solve the stated root causes:

Snapshot isolation addresses concurrency behavior, not malformed JSON or duplicate payload detection.

A trigger to rewrite malformed JSON is not the right integrity control and is brittle.

Foreign key constraints enforce referential integrity, not JSON validity or duplicate-payload prevention