QREP Practice Questions
Prepare for QREP with more than an answer.
- Exam fee
- $250 USD
- Level
- Professional
- Valid for
- No expiration
Domains covered on the exam 4
- Design47%
- Operations8%
- Troubleshooting22%
- Administration23%
- 1
A Qlik Replicate task uses Batch optimized apply mode. What is the primary purpose of the 'Force apply a batch when processing a DDL' option in the task's error handling settings?
Show answer details
Correct answer: C
In Batch optimized apply mode, changes are cached and applied in batches. If a DDL statement (like ALTER TABLE) arrives, it could fail if applied before the cached DML statements that precede it. This option forces Replicate to apply the current batch of cached changes first, ensuring the database state is consistent before the DDL statement is executed.
- 2
True or False: The Qlik Replicate Log Stream feature allows forwarding of server-level logs but not task-specific logs to an external monitoring system.
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Correct answer: B
The Log Stream feature is comprehensive and can be configured to forward both server-level logs (repsrv.log) and individual task logs to external systems like Splunk or Elastic Stack. This allows for centralized logging and monitoring of the entire Replicate environment.
- 3
A replication task from MySQL to a file-based target on a network share is experiencing intermittent failures with 'access denied' errors when writing files. The Qlik Replicate service runs as Local System. The network share has granted 'Full Control' to the machine account of the Replicate server (e.g.,
DOMAIN\REPSRV$). What is the most likely cause of the failure?Show answer details
Correct answer: C
While granting permissions to the machine account can sometimes work, it's often unreliable and depends on network security configurations. The standard and most reliable best practice for accessing network resources is to run the Qlik Replicate service under a dedicated domain service account and grant that specific account the necessary permissions on the network share.
- 4
When designing a task to replicate data to a data warehouse, an architect must decide on the method for handling deleted records from the source. The business requirement is to keep a historical record of all rows ever present in the source system, marking them as 'inactive' in the target rather than physically deleting them. Which feature should be used to achieve this?
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Correct answer: C
This requirement describes a 'soft delete' pattern. This is achieved by adding a new column to the target table (e.g., 'is_active'). Then, in the transformation settings for DELETE operations, you instruct Replicate to perform an UPDATE instead, setting the 'is_active' flag to 'false' or '0'. This preserves the record in the target while indicating it was deleted from the source.
- 5
Case Study
PharmaCore, a pharmaceutical research company, uses Qlik Replicate to consolidate clinical trial data from various global sites into a central SQL Server database. Each site has its own PostgreSQL database. A new regulation requires an immutable audit trail of all data changes.
Current Setup: 50 individual Qlik Replicate tasks, one for each research site's PostgreSQL database, replicate data to the central SQL Server. The tasks run in 'Batch optimized apply' mode for performance.
New Requirement: For every INSERT, UPDATE, and DELETE operation on the source tables, a corresponding record must be created in a set of 'audit' tables in the central database. These audit tables should store the before and after images of the data, the operation type, commit timestamp, and the transaction ID. The solution must not significantly impact the performance of the existing replication to the primary tables.
Constraints: The source PostgreSQL databases cannot be modified. The solution should be implemented within the existing Qlik Replicate environment.
How should the architect design the solution to meet the new audit trail requirement?
graph TD subgraph Site A PG1[PostgreSQL DB] end subgraph Site B PG2[PostgreSQL DB] end subgraph ... PG_N[...] end subgraph Central Data Center RepSrv[Qlik Replicate Server] SQL_DB[SQL Server] end PG1 --> RepSrv PG2 --> RepSrv PG_N --> RepSrv RepSrv --> SQL_DBShow answer details
Correct answer: B
The 'Store Changes' feature is purpose-built for creating audit trails. When enabled, Replicate creates a 'change table' for each source table on the target. This table automatically captures the before and after images, operation type, headers with timestamp and transaction ID, and other metadata. It's the most direct, efficient, and scalable way to meet the requirement without complex custom transformations or adding significant load to the existing apply process.
- 6
A financial services company is using Qlik Replicate to stream transactional data from an on-premises Oracle database to a Kafka topic. During a period of high market volatility, the replication task latency increases significantly, and the task eventually fails with 'out of memory' errors. The Replicate server has 64GB of RAM. Which configuration change is most likely to provide a stable, long-term solution for handling these data bursts?
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Correct answer: B
Enabling 'Store changes on disk' allows Replicate to offload in-flight transactions from memory to disk when memory pressure is high. This is the most effective mechanism for handling large transactional bursts that exceed available RAM, preventing 'out of memory' errors and providing a stable solution for volatile workloads without requiring a server hardware upgrade.
- 7
An administrator is setting up a new Qlik Replicate environment and needs to define user roles based on the principle of least privilege. The requirements are to create a role for junior operators who can only monitor tasks and another role for developers who can design and run tasks but not manage server settings or users. Which set of permissions correctly maps to these requirements?
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Correct answer: C
The 'Monitor' role is specifically designed for viewing and monitoring tasks, which fits the junior operator requirement. The 'Designer' role allows creating and editing tasks, and the 'Operator' role allows running and stopping them. Combining 'Designer' and 'Operator' gives developers the necessary permissions to manage the entire lifecycle of their tasks without granting them administrative access to server settings or user management.
- 8
A replication task from SQL Server to Snowflake has failed. The task log shows a primary key violation error for a specific table. The administrator queries the
attrep_apply_exceptionstable and finds an entry corresponding to the failure. TheOPERATIONcolumn for the failed record shows 'U' (Update). What is the most probable cause of this issue?Show answer details
Correct answer: D
A common cause for this scenario is when a DELETE operation is followed quickly by an INSERT with the same primary key on the source. If replication latency or batching causes the subsequent INSERT to be processed by Replicate before the DELETE, it will be translated as an UPDATE on the target. If the original record hasn't been loaded or was already deleted by another process, this UPDATE will fail because the target row doesn't exist, leading to an error that often manifests as a PK violation when Replicate tries to insert the missing record.
- 9
An architect is designing a data replication solution for a retail company. The primary requirement is to replicate sales data from 20 regional PostgreSQL databases to a central Amazon S3 data lake. The data must be transformed to a standardized Parquet format, and personally identifiable information (PII) like customer names and addresses must be masked using a SHA-256 hash function before being written to the target. What is the most efficient way to implement this PII masking requirement for all 20 tasks?
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Correct answer: C
Global Transformations are designed for applying a consistent rule across multiple tables and tasks. This approach is the most efficient and maintainable because the PII masking logic is defined once and automatically applied to any column matching the specified criteria in any of the 20 tasks, ensuring consistency and reducing manual configuration effort.
- 10
A Qlik Replicate task is configured with 'Store Changes' to create change tables in a staging database. A separate 'Apply Changes' task then reads from these change tables to update a data warehouse. This two-task architecture has been chosen to decouple data capture from data application. If the 'Apply Changes' task fails repeatedly due to a data type mismatch, what is the correct operational procedure to resolve the issue without losing the captured changes?
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Correct answer: B
The key benefit of the 'Store Changes'/'Apply Changes' architecture is decoupling. The 'Store Changes' task can continue capturing data independently. The correct procedure is to stop only the failing 'Apply Changes' task, modify its transformation or target table definition to fix the data type issue, and then resume it. Replicate will process the changes from where it left off in the change tables, ensuring no data loss.
