1. A non-transitory computer-readable medium storing computer-executable instructions that when executed by a computer cause the computer to: extract tax related data from a tax transaction database that stores a plurality of data records describing a plurality of tax return forms filed by a plurality of taxpayers, where each record includes values in tax return fields describing a taxpayer who filed the tax return form, further where the tax return fields include tax return lines; transform and store the extracted tax related data in a tax data warehouse that includes fact tables and dimension tables in at least one star schema by populating a fact table with i) values in the tax return form lines and ii) a form type identifier that identifies a type of the tax return form, where populating the fact table with values according to tax return form lines improves a granularity of analysis that can be performed using the tax data warehouse as compared to the tax transaction database; where the tax data warehouse includes a dimension table that has i) a row for each tax form type and ii) columns storing contextual information about tax return form lines; generate and store a plurality of key performance indicator (KPI) queries where each KPI query includes a different combination of tax metrics from the tax transaction database and one or more query elements associated with a criteria from the tax metrics; generate a plurality of materialized views where each materialized view corresponds to one of the plurality of KPI queries and stores aggregated key performance indicator (KPI) values for the corresponding KPI query; store the plurality of materialized views in the tax data warehouse for use in processing KPI queries; provide and display an interface that displays one or more of the plurality of KPI queries for selection; and in response to a first KPI query being selected, cause the first KPI query to be executed on at least a first materialized view from the plurality of materialized views that corresponds to the first KPI query to return results corresponding to the first KPI query.