# Platform Capabilities

This section collects cross-cutting how-to guides for working with a
deployed Dorieh data platform. Unlike the flagship
[climate tutorial](tutorial/climate/index.md) and the
[Medicare case study](Medicare.md), which each walk through building one
pipeline end to end, the pages below apply regardless of which data
domain you are working with: querying the database, monitoring its
activity, and describing user requests for research data.

```{toctree}
---
maxdepth: 1
caption: Capabilities
---
How to query the database <SampleQuery>
Querying Medicaid Data <QueringMedicaid>
Monitoring database activity <MonitoringDB>
Approximate distinct counting with HLL <UsingHLL>
Handling user requests <UserRequests>
Example user request <example_request_yaml>
```

What each guide covers:

* [How to query the database](SampleQuery.md) — sample SQL against the
  warehouse, including joins across domains.
* [Querying Medicaid Data](QueringMedicaid.md) — a discussion of
  querying health data specifically, with its privacy caveats.
* [Monitoring database activity](MonitoringDB.md) — Dorieh utilities
  for watching long-running database operations such as indexing.
* [Approximate distinct counting with HLL](UsingHLL.md) — how the QC
  tables use HyperLogLog sketches to count distinct beneficiaries
  cheaply.
* [Handling user requests](UserRequests.md) and the
  [example request](example_request_yaml.md) — describing research
  data requests declaratively in YAML.

```{seealso}
The generated [Data Dictionaries](dictionaries.md) — a page for every
table and column, with lineage diagrams — are the companion reference
for all the querying guides above.
```

The guides above apply to every data domain Dorieh supports — not
only the flagship climate and Medicare examples but also
[exposure data](exposures.md), [EPA data](epa.md) and
[census demographics](census.rst); see the
[Data Domains](domains.md) page for the full list.