> Documentation index: https://www.gooddata.ai/docs/gooddata-ui/llms.txt lists every page of these docs as Markdown.

# Execution

> Define what the backend computes and how the result is shaped: dimensions, sorting, totals, derived measures, and data sampling.

Describe a computation for the Analytical Backend and read its result. Start with the execution model, then set dimensions and sorting, add totals or derived measures, and trade accuracy for speed with data sampling.

## Pages

- [Execution model](https://www.gooddata.ai/docs/gooddata-ui/latest/data-layer/execution/execution-model/index.md): Create, inspect, and modify execution attributes, filters, measures, and sort items with SDK model factories, builders, and accessors.
- [Custom executions](https://www.gooddata.ai/docs/gooddata-ui/latest/data-layer/execution/custom-executions/index.md): Build custom executions with attributes, measures, filters, sorting, and dimensions via the Analytical Backend fluent API.
- [Result structure](https://www.gooddata.ai/docs/gooddata-ui/latest/data-layer/execution/result-structure/index.md): Define execution dimensions, totals, and sorting, then read computed data through execution results, data views, and DataViewFacade.
- [Table totals](https://www.gooddata.ai/docs/gooddata-ui/latest/data-layer/execution/table-totals/index.md): Add grand totals and subtotals to Pivot Tables with newTotal, covering sum, avg, min, max, median, and rollup aggregations.
- [Time-over-time comparison](https://www.gooddata.ai/docs/gooddata-ui/latest/data-layer/execution/time-over-time/index.md): Create same-period-last-year and previous-period derived measures with newPopMeasure and newPreviousPeriodMeasure.
- [Data sampling](https://www.gooddata.ai/docs/gooddata-ui/latest/data-layer/execution/data-sampling/index.md): Speed up visualizations by processing a percentage of dataset rows using the execConfig dataSamplingPercentage option.