The Evolution of Snowflake Documentation: From Static Documents to Living Systems
Documentation has long been the unsung hero of successful data platforms. Yet for most Snowflake teams, documentation remains a painful afterthought—created reluctantly, updated rarely, and consulted only in emergencies. This doesn't reflect a lack of understanding about documentation's importance, but rather the challenges inherent in creating and maintaining it in rapidly evolving data environments.
As someone who has implemented Snowflake across organizations ranging from startups to Fortune 500 companies, I've witnessed firsthand the evolution of documentation approaches. The journey from static Word documents to living, automated systems represents not just a technological shift, but a fundamental rethinking of what documentation is and how it creates value.
Let's explore this evolution and what it means for modern Snowflake teams.
The Documentation Dark Ages: Static Documents and Spreadsheets
In the early days of data warehousing, documentation typically took the form of:
These artifacts shared several critical weaknesses:
1. Immediate Obsolescence
The moment a document was completed, it began growing stale. With each database change, the gap between documentation and reality widened.
As one data warehouse architect told me: "We'd spend weeks creating beautiful documentation, and within a month, it was like looking at an archaeological artifact—interesting historically but dangerous to rely on for current work."
2. Disconnection from Workflows
Documentation lived separately from the actual work. A typical workflow looked like:
3. Limited Accessibility and Discoverability
Static documents were often:
4. Manual Maintenance Burden
Keeping documentation current required dedicated, manual effort that rarely survived contact with urgent production issues and tight deadlines.
A senior Snowflake administrator at a financial institution described it this way: "Documentation was always the thing we planned to do 'next sprint'—for about two years straight."
The Middle Ages: Wiki-Based Documentation
The next evolutionary stage saw documentation move to collaborative wiki platforms like Confluence, SharePoint wikis, and internal knowledge bases. This brought several improvements:
1. Collaborative Editing
Multiple team members could update documentation, distributing the maintenance burden and reducing bottlenecks.
2. Improved Discoverability
Wikis offered better search capabilities, linking between pages, and organization through spaces and hierarchies.
3. Rich Media Support
Teams could embed diagrams, videos, and interactive elements to enhance understanding.
4. Version History
Changes were tracked, providing accountability and the ability to revert problematic updates.
Despite these advances, wiki-based documentation still suffered from fundamental limitations:
As one data engineering leader put it: "Our Confluence was like a beautiful garden with some meticulously maintained areas and others that had become completely overgrown."
The Renaissance: Documentation-as-Code
The next significant evolution came with the documentation-as-code movement, where documentation moved closer to the data artifacts it described.
Key developments included:
1. SQL Comments as Documentation
Teams began embedding documentation directly in SQL definitions:
CREATE OR REPLACE TABLE orders (
-- Unique identifier for each order
order_id VARCHAR(50),
-- Customer who placed the order
-- References customers.customer_id
customer_id VARCHAR(50),
-- When the order was placed
-- Timestamp in UTC
order_timestamp TIMESTAMP_NTZ,
-- Total order amount in USD
-- Includes taxes but excludes shipping
order_amount DECIMAL(18,2)
);
COMMENT ON TABLE orders IS 'Primary order table containing one record per customer order';
COMMENT ON COLUMN orders.order_id IS 'Unique identifier for each order';
COMMENT ON COLUMN orders.customer_id IS 'Customer who placed the order, references customers.customer_id';
This approach had several advantages:
2. Data Build Tool (dbt) Documentation
dbt's integrated documentation brought significant advances:
# In schema.yml
version: 2
models:
- name: orders
description: Primary order table containing one record per customer order
columns:
- name: order_id
description: Unique identifier for each order
tests:
- unique
- not_null
- name: customer_id
description: Customer who placed the order
tests:
- relationships:
to: ref('customers')
field: customer_id
- name: order_timestamp
description: When the order was placed (UTC)
- name: order_amount
description: Total order amount in USD (includes taxes, excludes shipping)
dbt documentation offered:
3. Version-Controlled Database Schemas
Tools like Flyway, Liquibase, and Snowflake's SchemaChange brought version control to database schemas, ensuring documentation and schema changes moved together through environments.
However, while documentation-as-code represented significant progress, challenges remained:
The Modern Era: Living Documentation Systems
Today, we're seeing the emergence of truly living documentation systems for Snowflake—documentation that automatically stays current, integrates across the data lifecycle, and delivers value beyond reference material.
1. Metadata-Driven Documentation
Modern approaches use Snowflake's metadata to automatically generate and update documentation:
# Example Python script to generate documentation from Snowflake metadata
import snowflake.connector
import markdown
import os
# Connect to Snowflake
conn = snowflake.connector.connect(
user=os.environ['SNOWFLAKE_USER'],
password=os.environ['SNOWFLAKE_PASSWORD'],
account=os.environ['SNOWFLAKE_ACCOUNT'],
warehouse='COMPUTE_WH',
database='ANALYTICS'
)
# Query to get table metadata
table_query = """
SELECT
t.table_schema,
t.table_name,
t.comment as table_description,
c.column_name,
c.data_type,
c.comment as column_description,
c.ordinal_position
FROM information_schema.tables t
JOIN information_schema.columns c
ON t.table_schema = c.table_schema
AND t.table_name = c.table_name
WHERE t.table_schema = 'SALES'
ORDER BY t.table_schema, t.table_name, c.ordinal_position
"""
cursor = conn.cursor()
cursor.execute(table_query)
tables = cursor.fetchall()
# Group by table
current_table = None
documentation = {}
for row in tables:
schema, table, table_desc, column, data_type, col_desc, position = row
if f"{schema}.{table}" not in documentation:
documentation[f"{schema}.{table}"] = {
"schema": schema,
"name": table,
"description": table_desc or "No description provided",
"columns": []
}
documentation[f"{schema}.{table}"]["columns"].append({
"name": column,
"type": data_type,
"description": col_desc or "No description provided",
"position": position
})
# Generate Markdown documentation
os.makedirs("docs/tables", exist_ok=True)
for table_key, table_info in documentation.items():
md_content = f"# {table_info['schema']}.{table_info['name']}\n\n"
md_content += f"{table_info['description']}\n\n"
md_content += "## Columns\n\n"
md_content += "| Column | Type | Description |\n"
md_content += "|--------|------|-------------|\n"
for column in sorted(table_info["columns"], key=lambda x: x["position"]):
md_content += f"| {column['name']} | {column['type']} | {column['description']} |\n"
with open(f"docs/tables/{table_info['schema']}_{table_info['name']}.md", "w") as f:
f.write(md_content)
print(f"Documentation generated for {len(documentation)} tables")
This approach ensures documentation:
2. Integrated Data Catalog Solutions
Modern data catalogs like Alation, Collibra, and Data.World provide comprehensive documentation solutions:
3. Data Contract Platforms
The newest evolution involves data contracts as executable documentation:
# Example data contract for a Snowflake table
name: orders
version: '1.0'
owner: sales_engineering
description: Primary order table containing one record per customer order
schema:
fields:
- name: order_id
type: string
format: uuid
constraints:
required: true
unique: true
description: Unique identifier for each order
- name: customer_id
type: string
constraints:
required: true
references:
table: customers
field: customer_id
description: Customer who placed the order
- name: order_timestamp
type: timestamp
constraints:
required: true
description: When the order was placed (UTC)
- name: order_amount
type: decimal
constraints:
required: true
minimum: 0
description: Total order amount in USD (includes taxes, excludes shipping)
quality:
rules:
- rule: "COUNT(*) WHERE order_amount < 0 = 0"
description: "Order amounts must be non-negative"
- rule: "COUNT(*) WHERE order_timestamp > CURRENT_TIMESTAMP() = 0"
description: "Order dates cannot be in the future"
freshness:
maximum_lag: 24h
contact: [email protected]
Data contracts:
4. Documentation Mesh Architectures
The most advanced organizations are implementing "documentation mesh" architectures that:
A VP of Data Architecture at a leading e-commerce company described their approach: "We stopped thinking about documentation as something separate from our data platform. It's a core capability—every piece of our platform has both a data component and a metadata component that documents it."
Implementing Living Documentation in Your Snowflake Environment
Based on these evolutionary trends, here are practical steps to implement living documentation for your Snowflake environment:
1. Establish Documentation Automation
Start with basic automation that extracts metadata from Snowflake:
# Schedule this script to run daily
def update_snowflake_documentation():
# Connect to Snowflake
ctx = snowflake.connector.connect(...)
# Extract metadata
metadata = extract_metadata(ctx)
# Generate documentation artifacts
generate_markdown_docs(metadata)
generate_data_dictionary(metadata)
update_catalog_system(metadata)
# Notify team
notify_documentation_update(metadata)
2. Implement Documentation-as-Code Practices
Make documentation part of your database change process:
-- Example of a well-documented database change script
-- File: V1.23__add_order_status.sql
-- Purpose: Add order status tracking to support the new Returns Processing feature
-- Author: Jane Smith
-- Date: 2023-04-15
-- Ticket: SNOW-1234
-- 1. Add new status column
ALTER TABLE orders
ADD COLUMN order_status VARCHAR(20);
-- Add descriptive comment
COMMENT ON COLUMN orders.order_status IS 'Current order status (New, Processing, Shipped, Delivered, Returned, Cancelled)';
-- 2. Backfill existing orders with 'Delivered' status
UPDATE orders
SET order_status = 'Delivered'
WHERE order_timestamp < CURRENT_TIMESTAMP();
-- 3. Make column required for new orders
ALTER TABLE orders
MODIFY COLUMN order_status SET NOT NULL;
-- 4. Add documentation to data dictionary
CALL update_data_dictionary('orders', 'Added order_status column to track order fulfillment state');
3. Implement Data Contracts
Start formalizing data contracts for your most critical data assets:
4. Create Documentation Feedback Loops
Establish mechanisms to continuously improve documentation:
5. Measure Documentation Effectiveness
Track metrics that show the impact of your documentation:
The Future: AI-Enhanced Living Documentation
Looking ahead, AI promises to further transform Snowflake documentation:
As one chief data officer put it: "The future of documentation isn't having to look for it at all—it's having the right information presented to you at the moment you need it."
Conclusion: From Documentation as a Product to Documentation as a Process
The evolution of Snowflake documentation reflects a fundamental shift in thinking—from documentation as a static product to documentation as a continuous, automated process integrated with the data lifecycle.
By embracing this evolution and implementing living documentation systems, Snowflake teams can:
The organizations that thrive in the data-driven era won't be those with the most documentation, but those with the most effective documentation systems—ones that deliver the right information, at the right time, with minimal manual effort.
The question is no longer "Do we have documentation?" but rather "Is our documentation alive?"
How has your organization's approach to Snowflake documentation evolved? Share your experiences and best practices in the comments below.
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