If you ask anybody, they will tell you that data is valuable.
But what they are likely referring to is data analytics (i.e. reporting, dashboarding, predictive analytics, etc.). This is the output of data. To get to this stage, where data is centralized and made easily available for analysis, you need a data pipeline.
This is where data engineering comes in.
A data engineer focuses on the sources of the data, the quality of the data, the structure, formatting, accessibility, security, governance, and so on. All of these are extremely important to generate value for the organization.
In this post, we look at what is a data pipeline, how it works, and what is its underlying architecture.
Data is water
This is a perfectly suitable solution and achieves the desired result. But, as the village expands and their water needs increase, these traditional methods may become too inefficient.
What’s needed is a new delivery method, one that increases the water supply easily and with far less effort.
A more efficient solution would be to build a pipeline that automatically takes the water from these sources and delivers it to the village. This may even open up new uses for water that were previously not possible. An analogy we like to use here at Infostrux is ‘data is water’.
We view data engineers similar to plumbers, creating a network of pipes that connect and deliver water to the consumer.
Thinking about data in this way, data engineers lay the ‘info’structure for reliable and trusted data to be delivered so that it is available and easy to use for business intelligence, reports, dashboards, and other applications.
It’s not just about piping data, a data engineer needs to be thoughtful about the quality of the data that is being passed through the pipes and how it will be used for business analysis.
This ensures only quality water (or data) is being delivered.
What is a data pipeline?
A data pipeline is similar to the above water pipeline example. Essentially, it’s a much more efficient mechanism to transfer data from point A to point B, with some intermediary steps in between.
The data producer (A) represents the various data sources. The in-between steps (C, D, and E) are where the data is ingested from the sources, cleaned, integrated, stored, modelled, documented, secured, and governed.
Finally, the data becomes usable by the data consumer (B) who creates reports, dashboards, and other data applications with the data.
- Google Analytics
- Various ad platforms
- Sensor data
- Cloud APIs
Here are some common data sources that a company may want to ingest into a data pipeline focusing on marketing data.
Raw – Data is ingested from the data sources. The raw data can be >structured, semi-structured, or unstructured. Using Snowflake, data can be loaded from the raw area with high velocity, high variety, and high volumes with ease.
Clean – Cleaning, or wrangling data, is the process of finding errors in your dataset and fixing them in preparation of analysis. This includes: typos, inconsistencies (e.g. CA, CAD, CAN, Canada, or LA, Los Angeles) incomplete information (e.g. dates that are missing the year), inaccuracies, irrelevancies, etc. This is where the raw data is transformed to more curated datasets.
Model – Data modeling is the process in which data is further refined into consistent structures of defined measures (things you can measure such as revenue, cost of goods, gross margin, units sold, etc.) and dimensions (things that cannot be measured such as area codes, sales associates, location, product type, date, etc.). In the modelling stage, you can also enhance your data by establishing hierarchies, setting units and currencies, and adding formulas to make your analysis easier and consistent.
Store – Data is stored in a data repository such as a data lake, data warehouses, or data marts. Depending on the needs of the business, each of these data stores serve different purposes.
Work & Staging – The Work & Staging areas are typically used by data engineers and data scientists to handle operational tasks for managing the data pipeline, preparing and testing some of the transformations.
After the data has been ingested, cleaned, modelled, and stored, it is ready for consumption.
Data consumers can now use clean and reliable data in meaningful ways from data visualization and reporting in a Business Intelligence (BI) tool, data science applications such as predictive and ML models, and ad hoc SQL queries.
ETL vs ELT?
A digital transformation has been taking place with many organizations migrating from on-premise servers to the cloud.
The transformation brings a host of benefits, which include a shift from traditional on-premise ETL data pipeline process to a cloud-based ELT process.
ELT stands for “extract, load, and transform” — it describes a data pipeline process where data is taken from a source, replicated, placed in a data storage, and then transformed.
- Extract – data is taken from a data source
- Load – the process of moving data into a data storage system such as a data lake, data warehouse, or data mart. In an ETL model, data goes into a staging area.
- Transform – the process of changing the data’s structure into consistent formats so that it can be used for analysis and other data applications
In an ETL model, transformations occur prior to the load phase, which results in a more complex data replication process. However, it is ideal when a destination requires a specific data format. ETL tools require processing engines prior to loading data into the destination. For organizations looking for data compliance and privacy, ETL is ideal since it cleans sensitive and secure data before sending it to the data warehouse.
With ELT, organizations can use a BI tool to transform data, thus removing a step and making the data loading process more streamlined. For cloud data warehouses, ELT is an optimal approach since organizations can transform their raw data at any time and avoid a step in the data pipeline.
One important advantage to using Snowflake data cloud platform is that transformations and data modeling use SQL, which is a common programming language familiar to most data teams. This allows data scientists and analysts in most organizations to work with the data in a language they all understand.
The benefits of ELT
ELT and cloud-based data warehouses and data lakes have several benefits over ETL and on-premises hardware.
- Flexibility – since data sources and formats can vary and change frequently, ELT provides the flexibility to produce transformations on demand. This enables you to replicate and transform your raw data when and however you need to. Using ETL requires configuration and transformations in advance.
- Scalability – cloud data platforms such as Snowflake offer usage-based pricing, which allows you near-unlimited scalability within seconds or minutes. In contrast, on-premises data warehouses require organizations to purchase, install, configure, and maintain new hardware as their storage needs increase. Among many other disadvantages of on-premise servers, it can increase costs significantly.
- Time to value – ELT transforms data within a target system, enabling data scientists and analysts to work with large volumes of data more quickly. Whereas ETL requires a labour and resource-intensive manual coding process to ensure data conformity and uniformity prior to loading or integrating data.
For further reading, check out: 5 Mistakes Organizations Commonly Make with Data