Data transformation is the process of changing the format, structure, or values of data.
Types of data transformations
Extraction and parsing Initial transformations are focused on shaping the format and structure of data to ensure its compatibility with both the destination system and the data already there. Example: Parsing fields out of a json object for loading to a relational database
Translation and mapping Some of the most basic data transformations involve the mapping and translation of data. Example: A column containing integers representing statuses can be mapped to the relevant status descriptions
Filtering, aggregation, and summarization Data transformation often slims data down and making it more manageable. Data may be consolidated by filtering out unnecessary fields, columns, and records. Example: Exclude records from certain types of organizations or aggregate data to a daily count
Enrichment and imputation Data from different sources can be merged to create denormalized, enriched information. Example: Create a table that has a contracted quantity and product usage
Indexing and ordering Data can be transformed so that it's ordered logically or to suit a data storage scheme. Example: Index data by timestamp
Anonymization and encryption Data containing personally identifiable information, or other information that could compromise privacy or security, should be anonymized before propagation. Example: Splitting an email address into two columns, keeping the domain and hashing the name
Modeling, typecasting, formatting, and renaming Transformations that reshape data without changing content. Example: Renaming a column for clarity