Files
SecondBrain/10 Knowledge/CTO Academy/Data/Metadata.md
T

121 lines
2.8 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
**Estimated reading time:** 911 minutes
## Definition
**Metadata** is data that describes other data.
It provides context needed to understand, discover, govern, and operate datasets.
## Simple Mental Model
> **Data is the book. Metadata is the title, author, table of contents, publication date, and description on the back.**
## How It Works
Metadata can be grouped into several categories.
### Technical Metadata
Table names, columns, data types, keys, schemas.
### Business Metadata
Business definitions, owners, descriptions, certified use.
### Operational Metadata
Refresh time, pipeline duration, row counts, success/failure.
### Governance Metadata
Owner, steward, classification, retention, access rules.
## Example
Without metadata:
```text
tbl_vw_agg_final_v2
dt
uid
cnt
sec
src
```
With metadata:
```text
Name: Daily Viewing Aggregate
Purpose: Daily content consumption reporting
Source: JW Player viewing events
Grain: One row per user/content/day
Owner: Audience team
Refresh: Daily 05:00
sec: Total valid watch seconds
```
## How It Fits Into the Bigger Picture
[[Data Lineage]] uses metadata to understand relationships.
[[Data Governance]] uses metadata to record ownership and classification.
[[Data Quality]] uses metadata to record rules and results.
[[Data Catalog]] makes metadata searchable.
## My Company / Real-World Context
Useful metadata could identify which audience dataset is certified, who owns it, how often it refreshes, and which source systems feed it.
## CTO Perspective
A mature organization moves knowledge from:
```text
People's heads
Documented metadata
Searchable organizational knowledge
```
The useful question is:
> **Is the metadata complete, current, discoverable, and actually used?**
### Questions to Ask
- Who owns this dataset?
- What business purpose does it serve?
- What is its [[Grain]]?
- Where does it come from?
- How often is it refreshed?
- Is it certified for business use?
- Can users discover this information without asking the original developer?
## Meeting Scenario
**Situation:** A new analyst finds four datasets that appear to contain audience information.
**Possible response:**
> "If the only way to know which dataset is trusted is tribal knowledge, that's a scalability problem. Let's make the owner, purpose, status, grain, source, and refresh information discoverable as metadata."
## Key Takeaways
- Metadata is data about data.
- Technical metadata explains structure.
- Business metadata explains meaning.
- Operational metadata explains processing and freshness.
- Governance metadata explains ownership and controls.
- [[Data Catalog]] makes metadata discoverable.
## Related Concepts
- [[Data Catalog]]
- [[Data Governance]]
- [[Data Lineage]]
- [[Data Quality]]
- [[Business Glossary]]
- [[Data Owner]]
- [[Data Steward]]
- [[Grain]]