totalCount

TotalCount is a common name for a variable or field that stores the total number of items in a collection, dataset, or result set. It is used to convey the full size of a dataset, independent of how many items are currently loaded, displayed, or filtered. In practice, totalCount often accompanies a subset of results, such as a page of items, to enable meaningful navigation and reporting.

In databases and queries, totalCount may be produced by separate counting operations, for example by a COUNT(*) query, or by an estimate when exact counts are expensive. In paginated APIs and user interfaces, totalCount lets clients render indicators like “Showing 1–10 of 2,345 items” and compute total pages for navigation. In GraphQL and REST APIs, totalCount is frequently included as metadata within a response envelope or as part of a connection type.

Common data types for totalCount are integer or long, depending on language and expected dataset size. The value may be exact or, in some systems, approximate or cached to improve performance. It may also be nullable if the total is unknown at the time of the response.

Pitfalls and considerations include potential inconsistencies if data changes between counting and retrieval, or if filters are applied differently in separate queries. Counting can be resource-intensive on large datasets, so some systems trade exactness for performance by using estimates or maintaining precomputed counts. Transparency about whether totalCount is exact or estimated, and ensuring it aligns with applied filters, are recommended practices.

Overall, totalCount serves as a foundational metadata item for understanding dataset size, pagination, reporting, and user experience across data-driven applications.