# Data Dictionary Overview

This document provides background context and links to detailed documentation for the Jira BigQuery analytics project.

## 🏢 Company Background

**TiDB Cloud** is a fully-managed Database-as-a-Service (DBaaS) platform built on TiDB, an open-source distributed SQL database that supports Hybrid Transactional and Analytical Processing (HTAP) workloads.

### Key Facts

- **Company**: TiDB Cloud (part of PingCAP)
- **Product**: Cloud-native distributed database platform
- **Technology**: Based on TiDB, compatible with MySQL protocol
- **Architecture**: Separates computing (TiDB) from storage (TiKV row-based, TiFlash columnar)
- **Key Features**: Horizontal scalability, financial-grade high availability, real-time HTAP

### Jira Projects

| Project        | Full Name                  | Description                                                     |
| -------------- | -------------------------- | --------------------------------------------------------------- |
| **TCID** | TiDB-Cloud-Ticket          | Global JSM customer-facing project for general TiDB Cloud technical tickets |
| **ST**   | Support Ticket             | Customer-facing fast-path support project for selected key accounts |
| **TCOC** | TiDB Cloud On-Call         | Global internal Jira OnCall project for TiDB Cloud escalations |
| **FRM**  | Feature Request Management | Internal engineering backlog for feature requests and product fixes |
| **APID** | APAC-Ticket                | Global JSM customer-facing project for APAC Self-Managed tickets |

## 📊 Data Tables

| Table      | Description                                            | Human Link | Doc ID |
| ---------- | ------------------------------------------------------ | ---------- | ------ |
| `ticket` | Main Jira ticket table (partitioned by `created_at`) | [ticket.md](./tables/ticket.md) | `ticket` |

## 📚 Classification Standards

We use a **multi-dimensional classification system** with 6 complementary dimensions:

| Dimension                 | Structure           | When Filled     | Human Link | Doc ID |
| ------------------------- | ------------------- | --------------- | ---------- | ------ |
| **Problem Pattern** | L1 → L2            | Creation/Triage | [problem](../context/category_problem.md) | `problem` |
| **Issue Type**      | Flat (6 categories) | Creation/Triage | [issue_type](../context/category_issue_type.md) | `issue_type` |
| **Problem Domain**  | Flat (array)        | Creation/Triage | [domain](../context/category_problem_domain.md) | `problem_domain` |
| **Root Cause**      | L1 → L2 → L3      | Resolution      | [root_cause](../context/category_root_cause.md) | `root_cause` |
| **Service Type**    | Flat (8 categories) | Resolution      | [service_type](../context/category_service_type.md) | `service_type` |
| **Wetech**          | L1 → L2 → L3      | Resolution      | [wetech](../context/category_wetech.md) | `wetech` (ST/APID only) |

For design philosophy and how dimensions work together, see [category_design.md](../context/category_design.md) (Doc ID: `category_design`).

## 🔧 Schema Design

| Topic | Human Link | Doc ID |
| ----- | ---------- | ------ |
| BigQuery schema philosophy | [data_schema](../context/data_schema_design.md) | `data_schema` |
| Data pipeline workflow | [pipeline](../context/jira_to_bigquery_pipeline.md) | `pipeline` |
| Jira projects & workflow | [jira](../context/jira.md) | `jira` |

## 📌 Glossary

### General Terms

| Term                   | Definition                                               |
| ---------------------- | -------------------------------------------------------- |
| **Ticket**       | Jira ticket, customer-reported issues or requests        |
| **Severity**     | S1 (urgent) → S4 (low)                                  |
| **Verified**     | Human-verified data (source of truth for reporting)      |
| **AI Predicted** | AI-generated classification (fallback when not verified) |

### TiDB Cloud Terms

| Term                   | Definition                                            |
| ---------------------- | ----------------------------------------------------- |
| **Organization** | Top-level billing entity containing multiple projects |
| **Project**      | Logical grouping containing multiple clusters         |
| **Cluster**      | Individual TiDB database instance                     |
| **Tenant**       | Customer/organization identifier                      |

### BigQuery Terms

| Term                | Definition                                                      |
| ------------------- | --------------------------------------------------------------- |
| **Partition** | Table partitioned by `created_at` (daily)                     |
| **UNNEST**    | Operator for expanding array fields                             |
| **COALESCE**  | Use `COALESCE(verified_*, ai_predicted_*)` for priority logic |