OLAP library that implements:
- in-memory multidimensional dataset (
PivotDataclass) - OLAP operations: roll-up, slice and dice (
SliceQueryclass) - pivot table data model with efficient totals/sub-totals calculation (
PivotTableclass) 
Official component page: PivotData Toolkit for .NET
- Getting Started
 - Aggregate Functions
 - Implement custom aggregator
 - Query/Filter the cube
 - Sort pivot table data by labels or values
 - Create HTML pivot table
 - Pivot a DataTable
 - Create Excel PivotTable
 - API Reference
 
- CsvDemo: how to aggregate data from CSV file
 - DynamicFormulaMeasure: how to define formula-based measure dynamically (with a user-entered string expression)
 - DynamicListGrouping: group objects by multiple fields and calculate aggregates
 - ExcelPivotTable: generates Excel PivotTable by PivotData's PivotTable
 - ParallelCube: how to perform parallel aggregation (use all CPU cores) and merge all results into one resulting cube
 - PivotTableMvc: MVC example that renders simple pivot table / charts (without PivotData Toolkit components)
 - QueryCube: how to make OLAP queries with SliceQuery class: slice, dice, filter, roll-up, calculate derived dimensions and measures
 
NReco.PivotData is in production use at SeekTable.com and PivotData microservice. NReco.PivotData is a pre-requisite for PivotData Toolkit components.
Copyright 2015-2025 Vitaliy Fedorchenko
Distributed under the PivotData OLAP library FREE license (see src/LICENSE): NReco.PivotData can be used for free only in non-SaaS apps with one single-server production deployment. In all other cases commercial license is required (can be purchased here).