Data Science and Machine Learning Questions

Your company built a TensorFlow neural-network model with a large number of neurons and layers. The model fits well for the training data. However, when tested against new data, it performs poorly. What method can you employ to address this?

• Threading

• Serialization

• Dropout Methods

• Dimensionality Reduction

You are building a model to make clothing recommendations. You know a user’s fashion preference is likely to change over time, so you build a data pipeline to stream new data back to the model as it becomes available. How should you use this data to train the model?

• Continuously retrain the model on just the new data.

• Continuously retrain the model on a combination of existing data and the new data.

• Train on the existing data while using the new data as your test set.

• Train on the new data while using the existing data as your test set.

You create an important report for your large team in Google Data Studio 360. The report uses Google BigQuery as its data source. You notice that visualizations are not showing data that is less than 1 hour old. What should you do?

• Disable caching by editing the report settings.

• Disable caching in BigQuery by editing table details.

• Refresh your browser tab showing the visualizations.

• Clear your browser history for the past hour then reload the tab showing the virtualizations.

An external customer provides you with a daily dump of data from their database. The data flows into Google Cloud Storage GCS as comma-separated values (CSV) files. You want to analyze this data in Google BigQuery, but the data could have rows that are formatted incorrectly or corrupted. How should you build this pipeline?

• Use federated data sources, and check data in the SQL query.

• Enable BigQuery monitoring in Google Stackdriver and create an alert.

• Import the data into BigQuery using the gcloud CLI and set max_bad_records to 0.

• Run a Google Cloud Dataflow batch pipeline to import the data into BigQuery, and push errors to another dead-letter table for analysis.

Your weather app queries a database every 15 minutes to get the current temperature. The frontend is powered by Google App Engine and server millions of users. How should you design the frontend to respond to a database failure?

• Issue a command to restart the database servers.

• Retry the query with exponential backoff, up to a cap of 15 minutes.

• Retry the query every second until it comes back online to minimize staleness of data.

• Reduce the query frequency to once every hour until the database comes back online.

You are creating a model to predict housing prices. Due to budget constraints, you must run it on a single resource-constrained virtual machine. Which learning algorithm should you use?

• Linear regression

• Logistic classification

• Recurrent neural network

• Feedforward neural network

You are building new real-time data warehouse for your company and will use Google BigQuery streaming inserts. There is no guarantee that data will only be sent in once but you do have a unique ID for each row of data and an event timestamp. You want to ensure that duplicates are not included while interactively querying data. Which query type should you use?

• Include ORDER BY DESC on timestamp column and LIMIT to 1.

• Use GROUP BY on the unique ID column and timestamp column and SUM on the values.

• Use the LAG window function with PARTITION by unique ID along with WHERE LAG IS NOT NULL.

• Use the ROW_NUMBER window function with PARTITION by unique ID along with WHERE row equals 1.

Your company is using WILDCARD tables to query data across multiple tables with similar names. The SQL statement is currently failing with the following error: # Syntax error : Expected end of statement but got "~" at [4:11] SELECT age FROM `bigquery-public-data.noaa_gsod.gsod` WHERE age != 99 AND _TABLE_SUFFIX = '1929' ORDER BY age DESC Which table name will make the SQL statement work correctly?

• `bigquery-public-data.noaa_gsod.gsod`

• `bigquery-public-data.noaa_gsod.gsod*`

• `bigquery-public-data.noaa_gsod.gsod?`

• `bigquery-public-data.noaa_gsod.gsod~`

Your company is in a highly regulated industry. One of your requirements is to ensure individual users have access only to the minimum amount of information required to do their jobs. You want to enforce this requirement with Google BigQuery. Which three approaches can you take? (Choose three.)

• Restrict BigQuery API access to approved users.

• Restrict access to tables by role.

• Disable writes to certain tables.

• Segregate data across multiple tables or databases.

• Ensure that the data is encrypted at all times.

You are designing a basket abandonment system for an ecommerce company. The system will send a message to a user based on these rules: <- No interaction by the user on the site for 1 hour Has added more than $30 worth of products to the basket <- Has not completed a transaction You use Google Cloud Dataflow to process the data and decide if a message should be sent. How should you design the pipeline?

• Use a fixed-time window with a duration of 60 minutes.

• Use a sliding time window with a duration of 60 minutes.

• Use a session window with a gap time duration of 60 minutes.

• Use a global window with a time based trigger with a delay of 60 minutes.