An aggregate data is the data that is the result of applying a process to combine data elements from different sources. The aggregate data is usually taken collectively or in summary form. In relational database technology, aggregate data refers to the values returned when one issues an aggregate function.

The query function examines the aspects of the data in the table to reflect the properties of many groups of rows instead of an individual row. For example, one might want to find the average amount of money that a customer pays for something or how many professors are employed in a certain university department.

In a larger scale as in a data warehouse, aggregate data gathers information from a wide variety of sources like databases around the world to general useful report that can spot patterns and trends. A company may have different table customer information, product table, prices table, sales tables, employee table and branch tables. Each of these tables may general reports base on their records. For example, the products table may generate report of all products or the sale table may generate a sales report and so on.

But managers and decision makes need more than that. They may need sales reports from different branches so data from two sources, sales and branches may be queried to get aggregate data. In the same manner, a manager may also want reports for what particular product is the top in sales of a particular employee in a particular branch around, say, France. In this case, several table may have to be queried.

Another example where aggregate data used is in an accounting data warehouse. In this data warehouse, the historical general ledger transactions are stored. To summarize the transactions by account, an aggregate data table would be used.

The use of aggregate data is intensively used not just in business but in all forms of statistics as well – whether it is in governance, biodiversity sampling, pharmaceutical laboratories and weather watch. Many governments rely on aggregate data taken from statistical surveys and empirical data to determine the economy and give assistance to the less privileged areas. Weather stations share aggregate data to spot patterns in the constantly changing weather.

In global business where the internet has become the main conduit, a data warehouse is for a company is becoming ubiquitous. These data warehouse aggregate diverse data from different sources and when used with an electronic tool for analysis, the results can give amazing insights into the corporate operation and behaviors of the buying public.

Business intelligence, a form of artificial intelligence, relies heavily on aggregate data to be really intelligent. Complex relationships of tables within the database are programmatically queried using complex structure query language (SQL) statements. The report, which consists of aggregate data, can then be electronically passed to decision makers however wide the scope of the organization is. Business intelligence can sense trends and patterns often without human intervention. Because of the database’ capability to sort, filter, group and rank data, whether aggregate or not, business intelligence alone can determine which is good for the company and give recommendations to decision makers.

In the field of robotics, aggregate data is also very useful. With a top notch algorithm, a robot can get individual data and relate them with other data to make new meanings. As words mix and match, new "learnings" can be acquired by a robot with aggregate data.

Gathering and aggregating data is very labor intensive for the computer most especially if the data warehouse get very frequently updated. High speed computers are employed as stand alone servers just for the purpose of aggregating data with the use of a relational database management system.