Infocepts Technologies Interview Questions, Process, and Tips

Broadcasting is a feature in Apache Spark that allows for efficient data distribution across cluster nodes.

• Broadcasting is used to efficiently distribute read-only data to all nodes in a Spark cluster.

• It helps reduce data shuffling and improve performance by avoiding unnecessary data transfers.

• Common use cases include broadcasting small lookup tables or configuration data.

• Example: Broadcasting a small reference dataset

ETL stands for Extract, Transform, Load. It is a process used to extract data from various sources, transform it into a consistent format, and load it into a target database.

• Extract: Data is extracted from multiple sources such as databases, files, APIs, etc.

• Transform: Data is cleaned, filtered, aggregated, and converted into a consistent format.

• Load: Transformed data is loaded into a target database or data warehouse ...read more

In Tableau, groups are used to combine related dimension members, while sets are used to create custom fields based on a condition.

• Groups in Tableau are used to combine related dimension members into higher-level categories. For example, grouping different product categories into a single 'Other' category.

• Sets in Tableau are used to create custom fields based on a condition. For example, creating a set of 'High Sales' ...read more

OLAP is used for analyzing historical data while OLTP is used for managing real-time transactional data.

• OLAP stands for Online Analytical Processing and is used for complex queries and data analysis.

• OLTP stands for Online Transactional Processing and is used for managing real-time transactional data.

• OLAP databases are optimized for read-heavy workloads while OLTP databases are optimized for write-heavy workloads.

• OLAP d...read more

Tableau filters include context filters, extract filters, data source filters, and user filters. Execution order is top-down.

• Context filters are applied first and limit the data set for subsequent filters.

• Extract filters are applied next, filtering data before it is extracted into Tableau.

• Data source filters are applied after extract filters, limiting the data at the data source level.

• User filters are applied last, all...read more

Tree map displays hierarchical data using nested rectangles, while heat map visualizes data using colors.

• Tree map organizes data in a hierarchical structure with nested rectangles

• Heat map uses colors to represent data values on a matrix

• Tree map is useful for showing proportions within a whole, while heat map is good for visualizing patterns or correlations in data

I have worked on creating a custom sales performance chart for tracking monthly revenue

• Utilized Excel to create a custom chart with data from multiple sources

• Implemented color coding to highlight trends and outliers

• Added interactive features for easy data analysis

• Presented the chart to senior management for decision-making purposes

Rank function assigns a unique rank to each row in the result set, while dense_rank function assigns a unique rank to each distinct row in the result set.

• Rank function leaves gaps in the ranking if there are ties, while dense_rank function does not leave gaps.

• Rank function is used to assign a unique rank to each row based on the specified order, while dense_rank function is used to assign a unique rank to each distinct...read more

UNION combines the results of two or more SELECT statements, while UNION ALL does the same but includes duplicates.

• UNION removes duplicates from the result set, while UNION ALL includes duplicates

• UNION is slower than UNION ALL because it has to perform an additional step to remove duplicates

• UNION requires the same number of columns in the SELECT statements, while UNION ALL does not have this requirement

I optimized the performance of the dashboard by streamlining data sources, improving data visualization, and implementing automated updates.

• Identified and removed unnecessary data sources to reduce load times

• Utilized data caching techniques to improve dashboard loading speed

• Implemented data visualization best practices to enhance user experience

• Set up automated data refresh schedules to ensure real-time updates

• Optimize...read more

Types of joins in SQL with examples

• Inner Join: Returns rows when there is a match in both tables. Example: SELECT * FROM table1 INNER JOIN table2 ON table1.id = table2.id

• Left Join: Returns all rows from the left table and the matched rows from the right table. Example: SELECT * FROM table1 LEFT JOIN table2 ON table1.id = table2.id

• Right Join: Returns all rows from the right table and the matched rows from the left table...read more

Python has various data types including int, float, str, list, tuple, dict, set, bool, and more.

• int - integer numbers (e.g. 5)

• float - floating point numbers (e.g. 3.14)

• str - strings (e.g. 'hello')

• list - ordered collection of items (e.g. [1, 2, 3])

• tuple - ordered collection of items that cannot be changed (e.g. (1, 2, 3))

• dict - collection of key-value pairs (e.g. {'name': 'John', 'age': 30})

• set - unordered collection of...read more

Various ML algorithms include linear regression, decision trees, random forests, support vector machines, and neural networks.

• Linear Regression: Used for predicting continuous values based on input features.

• Decision Trees: Tree-like model of decisions used for classification and regression.

• Random Forests: Ensemble learning method using multiple decision trees for improved accuracy.

• Support Vector Machines: Classify data...read more