DP-800 exam tips: how to pass first time
The best DP-800 exam tip is to identify the one constraint in each scenario that decides the answer: latency, tamper-evidence, who must see plaintext, whether a transaction may wait. Most wrong answers are real features that solve a different problem. Beyond that, these tips cover the traps that the outline makes likely.
Read the code, not the feature name
Many items show T-SQL and ask what it does. Take a few seconds to trace it: which rows come back, what the window frame is, whether CROSS APPLY or OUTER APPLY drops unmatched rows, whether a trigger handles many rows. Do not guess from keywords.
Security: match the feature to the threat
| Requirement | Answer | Trap |
|---|---|---|
| Hide values in results from most users | Dynamic Data Masking | It is not encryption |
| Server and admins must never see plaintext | Always Encrypted | Limits what queries can do |
| Users see only their rows | Row-Level Security | A filter predicate does not stop bad writes; add a block predicate |
| Prove data was not altered | Ledger table | Not a history feature |
| Shared app login, per-user rows | SESSION_CONTEXT in the predicate | USER_NAME() would be the shared account |
Performance: symptom first
- Slow after a deployment with a new plan: Query Store, force the earlier plan.
- Sessions waiting but progressing: blocking. Two sessions each waiting for the other: deadlock, fix with consistent access order.
- Readers blocked by writers: consider row versioning isolation.
- A scalar function in a
SELECTover many rows: suspect per-row execution.
CI/CD: source control is the truth
The project is the source of truth for the schema. Out-of-band changes are drift. Secrets belong in a secret store, not in the repository. Production deployments need approvals and protected environments.
AI: ask four questions
- Exact words or meaning? Full-text, vector or hybrid.
- How big is the table and how strict is latency? Exact search or approximate search with an index.
- Can the transaction wait for a model call? Almost never; go asynchronous.
- Where does the key live? Prefer managed identity over stored keys.
Words that decide the answer
| Word in the scenario | Points toward |
|---|---|
| least privilege | Narrowest role or permission |
| tamper-evident | Ledger |
| as of a past date | Temporal table |
| without changing application code | Engine feature, not an app change |
| asynchronous, near real time | Change Tracking or CDC plus a function |
| approximate is acceptable | ANN with a vector index |
Use the time
You have 120 minutes. Answer what you know on the first pass, flag long code traces and return to them. For multiple-answer items, check how many answers are required before you pick. Do not change an answer unless you can name the reason.
Preparation habits that pay off
- Run every feature at least once. A masked column you queried yourself is remembered longer than one you read about.
- Work from the current outline; features in this area change quickly, and the outline changes on October 19, 2026.
- Take the practice test under time pressure and review every wrong answer by domain.
- Keep a list of functions by purpose: JSON, regular expression, fuzzy, vector. The exam names them.
For logistics on the day, see the exam day guide, and for difficulty, is DP-800 hard?.