Pass the Databricks ML Data Scientist Databricks-Machine-Learning-Professional Questions and answers with ExamsMirror

Real-time deployment is a type of model deployment where predictions are computed on-demand at query time. This can be useful when the feature values are not available until the time of delivery, and results are needed exceedingly fast for one record at a time. Real-time deployment can leverage Databricks Model Serving, which allows users to host MLflow models as REST endpoints on Databricks1. The other options are incorrect because they either do not meet the requirements or are not supported by Databricks Machine Learning. Edge/on-device deployment is a type of model deployment where predictions are computed on the edge device, such as a smartphone or a sensor. This can be useful when there is limited or no network connectivity, or when privacy and security are important. However, edge deployment is not supported by Databricks Machine Learning2. Streaming deployment is a type of model deployment where predictions are computed on streaming data, such as sensor readings or web logs. This can be useful when the data volume is high and the results need to be updated continuously. However, streaming deployment is not supported by Databricks Model Serving1. Batch deployment is a type of model deployment where predictions are computed in advance and stored for later use. This can be useful when the feature values are known ahead of time and the predictions do not need to be delivered quickly. However, batch deployment does not meet the requirements of this scenario, as the feature values are not available until the time of delivery, and results are needed exceedingly fast for one record at a time. References: MLflow Model Serving, Model deployment patterns

The Databricks REST APIs allow users to programmatically access Databricks features and services, such as clusters, jobs, workspaces, libraries, secrets, and more. The Jobs API enables users to create, edit, delete, run, and list jobs, as well as manage job runs. Users can use the Jobs API to programmatically create a new Databricks job whose schedule depends on the result of some automated tests in a machine learning pipeline. For example, users can use the create endpoint to create a new job with a cron_schedule parameter that specifies the cron expression for the job schedule. Users can also use the run_now endpoint to run an existing job with a run_name parameter that specifies the name of the run. Users can use the runs/get endpoint to get the run result state of a job run, and use conditional logic to trigger another job run based on the result. Users can also use the runs/list endpoint to list all the runs of a job, and use the runs/cancel endpoint to cancel a job run if needed. References:

Databricks REST API — Databricks Documentation, p. 1

Jobs API — Databricks Documentation, p. 1-2

Create and run Databricks Jobs | Databricks on AWS, Create and run jobs using the CLI, API, or notebooks, p. 1

A two-way Chi-squared test is a statistical test that can be used to compare the frequencies of categorical variables across two or more groups. In this case, the engineer can use a two-way Chi-squared test to compare the frequencies of the categorical input variable values across different time periods (e.g., months, quarters, etc.) and see if there is a significant difference in the proportion of missing values. A significant difference would indicate that the missing values are not randomly distributed and may affect the performance of the machine learning model. References:

Databricks Machine Learning Professional Exam Guide, Section 4: Solution and Data Monitoring, p. 5

Databricks Machine Learning Documentation, Monitoring ML Models, Data Drift Detection, p. 3

The client.delete_registered_model method of the MlflowClient class can be used to delete a model from the MLflow Model Registry. The method takes the following parameter:

name: The name of the registered model to delete.

The method deletes the registered model and all its versions from the Model Registry. The method does not return any value1

The other options are incorrect because:

A. The client.transition_model_version_stage method can be used to transition a model version to a different stage, such as None, Staging, Production, or Archived. The method does not delete the model or the model version from the Model Registry2

B. The client.delete_model_version method can be used to delete a specific model version from the Model Registry. The method does not delete the registered model or all its versions from the Model Registry3

C. The client.update_registered_model method can be used to update the metadata of a registered model, such as its name or description. The method does not delete the model or its versions from the Model Registry4

D. There is no method called client.delete_model. To delete a model from the Model Registry, the client.delete_registered_model method should be used.

References:

mlflow.tracking.client.MlflowClient.delete_registered_model — MLflow 2.9.1 documentation

mlflow.tracking.client.MlflowClient.transition_model_version_stage — MLflow 2.9.1 documentation

mlflow.tracking.client.MlflowClient.delete_model_version — MLflow 2.9.1 documentation

mlflow.tracking.client.MlflowClient.update_registered_model — MLflow 2.9.1 documentation

The Model Registry is a centralized model store that allows you to manage the full lifecycle of MLflow Models. It provides model lineage, versioning, stage transitions, and annotations. You can use the Model Registry to discover and share models, collaborate on moving them from experimentation to production, integrate with approval and governance workflows, and monitor model deployments and performance1. The other options are incorrect because:

Option A: Models is a component of MLflow that allows you to manage and deploy models from a variety of ML libraries to a variety of model serving and inference platforms. Models is not a centralized model store, but rather a convention for packaging machine learning models that offers self-contained code, environments, and models2.

Option C: Model Serving is a feature of Databricks that allows you to host MLflow Models as REST endpoints. Model Serving is not a centralized model store, but rather a model deployment option that enables low-latency inference for real-time applications3.

Option D: Feature Store is a feature of Databricks that allows you to store, discover, and share features for machine learning. Feature Store is not a centralized model store, but rather a centralized feature store that enables feature reuse, consistency, and governance across ML projects4.

Option E: Experiments is a component of MLflow that allows you to track experiments to record and compare parameters and results. Experiments is not a centralized model store, but rather a logging service that stores runs, metrics,parameters, tags, and artifacts for each experiment. References: MLflow Model Registry, MLflow Models, MLflow Model Serving, Databricks Feature Store, [MLflow Tracking]

To restore the original scikit-learn model object, the correct method is mlflow.sklearn.load_model, which takes the model URI as an argument and returns a scikit-learn model. This method can load models with the sklearn flavor, which preserves the original attributes and methods of the model. The mlflow.load_model method is a generic method that can load models with any flavor, but it returns a pyfunc model, which does not have the feature_importances_ attribute. The client.list_artifacts method is used to list theartifacts associated with a run, not to load a model. The client.pyfunc.load_model method is similar to mlflow.load_model, but it takes a local file path instead of a model URI. The MLflow Experiments UI can show the logged parameters, metrics, and artifacts of a run, but it cannot show the model object itself. References:

MLflow Models

MLflow Python API

The DESCRIBE HISTORY command can be used to view the commit history of a Delta table, including the schema changes, operations, and timestamps. This command can help identify when a column was dropped from the feature set and by which operation. The other commands are either invalid or do not provide the required information. References:

Delta Lake - View Commit History

Databricks Certified Machine Learning Professional Exam Guide - Section 1: Experimentation - Data Management

Z-Ordering is an optimization technique that can speed up the query by colocating similar records while considering values in multiple columns. Z-Ordering is a way of organizing data in storage based on the values of one or more columns. Z-Ordering maps multidimensional data to one dimension while preserving locality of the data points. This means that rows with similar values for the specified columns are stored close together in the same set of files. This improves the performance of queries that filter on those columns, as they can skip over irrelevant files or data blocks. Z-Ordering also enhances data skipping and caching, as it reduces the number of distinct values per file for the chosen columns1. The other options are incorrect because:

Option B: Bin-packing is an optimization technique that compacts small files into larger ones, but does not colocate similar records based on multiple columns. Bin-packing can improve the performance of queries by reducing the number of files that need to be read, but it does not affect the data layout within the files2.

Option C: Writing as a Parquet file is not an optimization technique, but a file format choice. Parquet is a columnar storage format that supports efficient compression and encoding schemes. Parquet can improve the performance of queries by reducing the storage footprint and the amount of data transferred, but it does not colocate similar records based on multiple columns3.

Option D: Data skipping is an optimization technique that skips over files or data blocks that do not match the query predicates, but does not colocate similar records based on multiple columns. Data skipping can improve the performance of queries by avoiding unnecessary data scans, but it depends on the data layout and the metadata collected for each file4.

Option E: Tuning the file size is an optimization technique that adjusts the size of the data files to a target value, but does not colocate similar records based on multiple columns. Tuning the file size can improve the performance of queries by balancing the trade-off between parallelism and overhead, but it does not affectthe data layout within the files5. References: Z-Ordering (multi-dimensional clustering), Compaction (bin-packing), Parquet, Data skipping, Tuning file sizes

Feature drift is a change in the distribution of the input data over time, which can affect the performance and accuracy of the model. Monitoring feature drift is important to ensure that the model is still valid and reliable for the current data. One simple and low-cost method of monitoring numeric feature drift is to track the summary statistics trends of the input features, such as mean, standard deviation, minimum, maximum, etc. These statistics can be computed easily and efficiently, and can provide a quick overview of the changes in the data distribution. If the summary statistics deviate significantly from the baseline values, it may indicate a feature drift. However, summary statistics trends may not capture all the nuances of the data distribution, such as outliers, multimodality, skewness, etc. Therefore, other methods, such as statistical tests or visualizations, may be needed to complement the summary statistics trends and provide a more comprehensive analysis of the feature drift123 References:

Monitoring Feature Drift - Databricks

Monitor feature attribution skew and drift | Vertex AI | Google Cloud

Monitoring Model Drift - 6 Different Methodologies - Qualdo

 The mlflow.register_model function takes two arguments: model_uri and name. The model_uri is the URI of the model that was logged to MLflow, which can be obtained from the best run object. The name is the name of the registered model in the MLflow Model Registry. Therefore, the correct line of code to register the model is:

mlflow.register_model(model_uri, “best_model”)

This will create a new registered model with the name “best_model” and register the model version from the best run as the first version of that model.

References:

[mlflow.register_model — MLflow 1.22.0 documentation]

[MLflow Model Registry — Databricks Documentation]

[Manage MLflow Models — Databricks Documentation] Message has links.