Data Acquisition Methods

Data Acquisition and Preparation (22%)

Data integration

The process of combining data from multiple sources into a unified view to support analysis, reporting, and decision-making.

Querying

The process of requesting specific data from a database or dataset using a query language to retrieve, filter, or manipulate information for analysis.

Join

Combines data from two or more tables based on a related column or key.

Concatenate

Combines two or more strings or datasets end-to-end into a single result.

Filter

Selects only the rows or records that meet specific criteria.

Union

Merges the results of two queries into a single dataset, removing duplicates if applicable.

Grouping

Organizes data into categories based on one or more columns to perform summary calculations.

Aggregate

Performs calculations on grouped or selected data.

Nested queries

A query contained within another query, allowing complex filtering or calculation.

Basic query optimization

Techniques to improve query performance.

Indexing

Creating data structures that allow faster retrieval of rows from a database table.

Parameterization

Using variables or placeholders in queries to make them reusable and more secure.

Subsets

Selecting a smaller portion of data from a larger dataset for analysis or testing.

Temporary tables

Short-lived tables created within a session to store intermediate results during query processing.

ETL/ELT

Processes for moving and transforming data. Extract, Transform, Load; extracts data from sources, transforms it, then loads it into a destination. Extract, Load, Transform; loads raw data first and transforms it within the destination system.

Surveying

Collecting data directly from individuals through structured questionnaires or forms.

Sampling

Selecting a smaller, representative subset of a larger population to analyze and draw conclusions.