DP-800 Premium File
- 101 Questions & Answers
- Last Update: Nov 12, 2026
A prompt-injection string stored in a comment tells the AI coding assistant to export a secrets table
Which SQL design or implementation decision most directly addresses this requirement?
Prompt injection in tool output must not grant new authority or override the application trust boundary.
Grounded schema context helps prevent nonexistent objects but still requires verification of generated SQL.
Generated SQL must meet normal secure-coding requirements; a model does not sanitize input automatically.
Copilot features depend on administrative eligibility and workspace settings rather than appearing automatically for every user.
An embedding worker retries after a timeout and adds a duplicate vector row for the same source version
Which SQL design or implementation decision most directly addresses this requirement?
Idempotent update/upsert logic prevents duplicate business vectors during retries and parallel workers.
CDC captures historical change records from the log, unlike key-only change tracking.
Functions can process detected row changes automatically but require connection, concurrency and retry safeguards.
Vector similarity does not enforce authorization; retrieval still needs tenant/ACL filters.
An AI assistant suggests a query rewrite that looks simpler but may lose a necessary tenant predicate
After the team applies the intended design, which observation would most directly verify that the specific requirement was met?
AI-generated rewrites can silently alter authorization or semantics even if syntactically valid.
AI-tool access should follow user authorization and workspace boundaries rather than tool availability alone.
Instruction files can guide generated suggestions toward local style and safety expectations, but must still be reviewed.
Least privilege reduces the impact of prompt injection, mistaken tool calls and credential disclosure.
A data-quality check needs to find rows containing a nonstandard identifier format
Which SQL design or implementation decision most directly addresses this requirement?
REGEXP_LIKE evaluates a regex match, including anchors that constrain the whole input rather than just a substring.
Errors can leave a transaction uncommittable; blindly committing from a catch block is unsafe.
DENSE_RANK retains equal ranks for ties while the next distinct value advances by one.
Window numbering can select one row per logical partition while a deterministic secondary sort resolves equal timestamps.
A registration table allows blank mandatory identifiers because no constraints were defined
After the team applies the intended design, which observation would most directly verify that the specific requirement was met?
Nullability is a core schema invariant and should not be delegated solely to an API form.
Referential constraints ensure stored relationships point to permitted parent keys and avoid orphan records.
Partition elimination can narrow scans and partition switching can simplify retention when indexes align.
Database check predicates reject invalid stored values regardless of which client sent the write.
A file naming convention encodes a region token inside a longer value
Which SQL design or implementation decision most directly addresses this requirement?
REGEXP_SUBSTR returns a matched substring while a boolean regex predicate only indicates match existence.
Window numbering can select one row per logical partition while a deterministic secondary sort resolves equal timestamps.
JSON membership testing asks whether a value is contained in the target JSON expression rather than extracting one scalar only.
REGEXP_COUNT returns the number of matches, unlike a boolean REGEXP_LIKE or substring extraction.
A rewards board requires tied customers to share a position but no rank gaps
Which SQL design or implementation decision most directly addresses this requirement?
DENSE_RANK retains equal ranks for ties while the next distinct value advances by one.
NOT EXISTS handles absence checks without the nullable-operand pitfalls that can affect NOT IN.
Graph MATCH expresses edge relationships in a pattern rather than merely comparing flat key columns.
Recursive CTEs need termination and data-integrity safeguards; a recursion cap is a protective limit, not a substitute for valid hierarchy rules.
An app treats snapshot write-conflict errors as though they can always be silently ignored
After the team applies the intended design, which observation would most directly verify that the specific requirement was met?
Optimistic versioned isolation can reject overlapping writes, requiring idempotent retry or conflict resolution.
The optimizer may scan without a suitable search path; index keys should reflect frequently filtered columns.
Blocking is caused by incompatible locks; addressing the head blocker is different from killing every waiting request.
Actual plans reveal runtime statistics and costly operators that estimated plans alone may not expose.
A DAB service exposes endpoints but role names differ from the organization's signed-in identities
Which SQL design or implementation decision most directly addresses this requirement?
Application identity, API entity permissions and SQL authorization must jointly prevent overbroad access.
Pagination bounds response size and limits database work per request, while stable ordering is essential.
Configuration separation allows consistent entities while credentials and endpoints differ securely across environments.
CES can publish database changes into an event architecture, but supported platform and ordering guarantees must be checked.
A search system changes embedding model version while keeping the same table and index
Which SQL design or implementation decision most directly addresses this requirement?
Different embedding models or versions need not share vector space; mixing vectors can destroy distance relevance.
CDC captures historical change records from the log, unlike key-only change tracking.
High-entropy IDs and timestamps add noise to natural-language embeddings; structured filters handle them better.
Operational logs can reveal sensitive source text or access tokens if not carefully configured.
A service should execute only a vetted stored procedure, not read the underlying HR table directly
Which SQL design or implementation decision most directly addresses this requirement?
Object-level permissions enable task-specific capability without broad exposure to every table.
TLS protects data in transit and endpoint verification reduces man-in-the-middle risk.
Deterministic encryption enables equality comparisons for matching plaintexts but reveals equality patterns and is less private than randomized encryption.
Network restrictions limit reachability while scoped credentials decide who can invoke supported operations.
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