Maintenance Tasks - Learning Module

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Documentation

Documentation: The Multiplier of Expertise

A database administrator who keeps all knowledge in their head is a liability, not an asset. When that person goes on vacation, gets sick, or leaves the organization, their knowledge leaves with them. Critical procedures become guesswork. Simple tasks become archeological expeditions.

Documentation transforms individual expertise into organizational capability.

Good documentation enables consistent operations regardless of who is on call. It reduces errors during stressful incidents. It accelerates onboarding of new team members. It provides the institutional memory that survives personnel changes.

Yet documentation is often neglected—seen as overhead rather than essential infrastructure. This is a mistake that compounds over time, creating technical debt that eventually manifests as extended outages and costly mistakes.

What You Will Learn

By the end of this page, you will understand the essential categories of database documentation, master runbook creation for operational procedures, develop architecture and configuration documentation, establish change logging and audit trails, and create disaster recovery documentation that works under pressure.

The Documentation Imperative

Database documentation serves multiple audiences and purposes. Understanding these helps prioritize what to document and how to structure it.

Primary audiences for database documentation:

On-call engineers: Need quick answers during incidents—"How do I restart this service? What's the escalation path?"
Operations team: Need standard procedures for routine maintenance and monitoring
New team members: Need to understand the environment and how things connect
Auditors and compliance: Need evidence of controls, procedures, and change management
Future selves: You in 6 months won't remember why you made that configuration choice

Essential Database Documentation Categories
Category	Purpose	Update Frequency	Primary Audience
Architecture Diagrams	Understand system topology and relationships	On significant changes	All
Configuration Documentation	Record settings and their rationale	When configs change	Operations, New hires
Operational Runbooks	Step-by-step procedures for common tasks	Quarterly review	Operations, On-call
Disaster Recovery Plans	Recovery procedures for major failures	Semi-annual review + test	All engineers
Change Logs	Record of all changes with context	Every change	All, Auditors
Incident Postmortems	Lessons learned from outages	After each incident	All engineers
Capacity Planning	Growth projections and resource planning	Quarterly	Management, DBAs
Security Documentation	Access controls, encryption, compliance	On policy changes	Security, Auditors

The Documentation Decay Problem

Documentation becomes outdated the moment it's written. Systems change, but docs don't get updated. Outdated documentation is often worse than no documentation—it misleads during critical moments. Build documentation review into your regular maintenance cycles.

Architecture Documentation

Architecture documentation provides the high-level view of database systems—what exists, how components connect, and why they're structured that way. This is often the first thing new team members need and the reference point during major changes.

Essential Architecture Diagrams

•Logical Architecture — Database instances, their purposes (OLTP, reporting, dev), and relationships. Shows what databases exist and their roles.
•Physical Topology — Servers, data centers, network connections, storage systems. Shows where databases run and how they connect.
•High Availability Architecture — Primary/replica relationships, failover mechanisms, load balancers. Shows how redundancy is achieved.
•Data Flow Diagram — How data moves between systems—ETL processes, replication, exports/imports. Shows data lineage.
•Backup Architecture — Backup targets, schedules, retention. Shows how data is protected.
•Security Architecture — Network zones, firewalls, encryption points, authentication flows. Shows security boundaries.

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# Database Architecture Documentation
 
## 1. Environment Overview
 
| Environment | Purpose        | Databases | HA Strategy   |
|-------------|----------------|-----------|---------------|
| Production  | Live workloads | OrdersDB, UsersDB, AnalyticsDB | Always On AG |
| Staging     | Pre-prod tests | OrdersDB, UsersDB | Single node |
| Development | Dev/Testing    | OrdersDB, UsersDB | Single node |
 
## 2. Production Cluster Topology
 
### Primary Datacenter (DC-EAST)
- **db-prod-01** (Primary for OrdersDB, UsersDB)
  - CPU: 64 cores | RAM: 512GB | Storage: 20TB SAN
  - IP: 10.0.1.10 | FQDN: db-prod-01.internal
 
- **db-prod-02** (Secondary Replica)
  - CPU: 64 cores | RAM: 512GB | Storage: 20TB SAN
  - IP: 10.0.1.11 | FQDN: db-prod-02.internal
 
### Secondary Datacenter (DC-WEST)
- **db-prod-03** (Async Replica for DR)
  - CPU: 64 cores | RAM: 512GB | Storage: 20TB SAN
  - IP: 10.1.1.10 | FQDN: db-prod-03.internal
 
## 3. Connection Information
 
### Application Connection Strings
```
Production Listener: prod-db-ag.internal:1433
Read-Only Routing: prod-db-ag.internal:1433;ApplicationIntent=ReadOnly
```
 
### Administrative Access
- Jump host: db-jump.internal (requires MFA)
- Direct RDP: Restricted to DB team (VPN + certificate)
 
## 4. Database Inventory
 
| Database   | Size    | Recovery Model | Backup Schedule      |
|------------|---------|----------------|----------------------|
| OrdersDB   | 2.1 TB  | Full           | Full: Daily 2AM, Log: 15min |
| UsersDB    | 150 GB  | Full           | Full: Daily 2AM, Log: 15min |
| AnalyticsDB| 5.4 TB  | Simple         | Full: Weekly Sun 3AM |
 
## 5. Replication Topology
 
```
[OrdersDB - Primary (db-prod-01)]
       │
       ├──> [Sync Replica (db-prod-02)] ──> Used for failover
       │
       └──> [Async Replica (db-prod-03)] ──> DR site, read offload
```
 
## 6. Network Architecture
 
```
Internet -> WAF -> App Servers (10.0.2.0/24)
                        │
                        v
             Load Balancer (10.0.1.5)
                        │
                        v
              Database Tier (10.0.1.0/24)
                   [Firewall: 1433 only from 10.0.2.0/24]
```
 
---
*Last Updated: 2024-01-15 by J. Smith*
*Review Schedule: Quarterly*

Diagram as Code

Consider using 'diagram as code' tools like Mermaid, PlantUML, or Graphviz. These allow diagrams to be version-controlled, diffed, and updated alongside other documentation. They're also easier to keep current than manually edited graphics.

Configuration Documentation

Configuration documentation records what settings are in place and why. The 'why' is crucial—it preserves the reasoning behind decisions so future engineers don't unknowingly reverse important changes.

Configuration Documentation Elements
Element	What to Document	Example
Server Parameters	All non-default settings with rationale	max_connections = 500 (anticipated peak: 400)
Memory Configuration	Buffer pools, caches, work memory	shared_buffers = 128GB (25% of 512GB RAM)
Storage Configuration	File locations, sizes, growth settings	Log file pre-sized to 100GB to prevent auto-growth
Security Settings	Authentication modes, encryption	SSL required for all connections
Replication Settings	Sync mode, timeouts, commit behavior	synchronous_commit = on for durability
Maintenance Settings	Autovacuum, checkpoints, jobs	checkpoint_timeout = 15min (balance recovery time vs performance)

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# PostgreSQL Configuration Documentation
## Server: db-prod-01
 
### Memory Configuration
 
| Parameter | Value | Default | Rationale |
|-----------|-------|---------|-----------|
| shared_buffers | 128GB | 128MB | 25% of 512GB RAM per PostgreSQL recommendations |
| effective_cache_size | 384GB | 4GB | 75% of RAM - OS cache + shared_buffers |
| work_mem | 256MB | 4MB | Higher for complex analytics queries. Caution: multiplied by (max_connections × sort operations) |
| maintenance_work_mem | 4GB | 64MB | Faster VACUUM, index builds. Only one maintenance op at a time per session |
 
**Note**: work_mem was increased from 64MB to 256MB on 2023-08-15 after 
analyzing slow sort operations. See ticket DB-1234 for analysis.
 
### Connection Configuration
 
| Parameter | Value | Default | Rationale |
|-----------|-------|---------|-----------|
| max_connections | 500 | 100 | Peak connections observed: 380. Headroom for spikes |
| superuser_reserved_connections | 5 | 3 | Ensure admin access during connection exhaustion |
 
**Warning**: max_connections × work_mem = potential 128GB memory usage for sorts.
If connection pool grows, may need to reduce work_mem.
 
### Write-Ahead Log (WAL) Configuration
 
| Parameter | Value | Default | Rationale |
|-----------|-------|---------|-----------|
| wal_level | replica | replica | Required for streaming replication |
| max_wal_senders | 5 | 10 | 2 standby + 3 backup connections |
| wal_keep_size | 4GB | 0 | Retain WAL for standby catchup during network issues |
| archive_mode | on | off | Required for PITR |
| archive_command | pgbackrest --stanza=main archive-push %p | - | Using pgBackRest for WAL archiving |
 
### Checkpoint Configuration
 
| Parameter | Value | Default | Rationale |
|-----------|-------|---------|-----------|
| checkpoint_timeout | 15min | 5min | Reduce checkpoint frequency, accept longer recovery |
| checkpoint_completion_target | 0.9 | 0.9 | Spread checkpoint I/O over 90% of interval |
| max_wal_size | 8GB | 1GB | Allow more WAL between checkpoints |
 
**Trade-off**: Longer checkpoint intervals improve write performance but 
extend crash recovery time. Current setting = ~10 min recovery time.
 
---
*Reviewed: 2024-01-01 by DBA Team*
*Next Review: 2024-04-01*

Operational Runbooks

Runbooks are step-by-step procedures for common operational tasks. They enable consistent execution regardless of who performs the task and are invaluable during high-stress incidents when clear thinking is compromised.

Characteristics of effective runbooks:

Prescriptive: Tell the reader exactly what to do, not just what to consider
Complete: Include all steps, including verification and rollback
Tested: Have been executed successfully; ideally, regularly rehearsed
Accessible: Easy to find under pressure; available when systems are down

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# Runbook: Database Failover to DR Site
 
## Overview
- **Purpose**: Failover production databases from DC-EAST to DC-WEST
- **When to Use**: Primary datacenter failure, planned maintenance, DR drill
- **Duration**: ~15 minutes (planned), ~30 minutes (unplanned)
- **Impact**: Brief connection interruption during DNS update
- **Owner**: Database Team
- **Last Tested**: 2024-01-10 (quarterly DR drill)
 
## Prerequisites
- [ ] Confirm DR replica is synchronized (lag < 5 seconds)
- [ ] Notify Application Team (app-team@company.com)
- [ ] Notify NOC (noc@company.com)
- [ ] Ensure you have admin access to DR site
 
## Procedure
 
### Step 1: Assess Current State
```sql
-- Run on DR replica to check synchronization
SELECT 
    database_name,
    synchronization_state_desc,
    synchronization_health_desc,
    secondary_lag_seconds
FROM sys.dm_hadr_database_replica_states
WHERE is_local = 1;
```
**Expected**: synchronization_state = SYNCHRONIZED, lag < 5 seconds
 
### Step 2: Verify DR Replica Readiness
```powershell
# Check replica is accessible
Test-NetConnection -ComputerName db-prod-03.internal -Port 1433
```
**Expected**: TcpTestSucceeded = True
 
### Step 3: Initiate Failover
 
#### If Primary is Available (Graceful):
```sql
-- Run on PRIMARY (db-prod-01)
ALTER AVAILABILITY GROUP [ProdAG] FAILOVER;
```
 
#### If Primary is Unavailable (Forced):
```sql
-- Run on DR replica (db-prod-03)
ALTER AVAILABILITY GROUP [ProdAG] 
FORCE_FAILOVER_ALLOW_DATA_LOSS;
```
⚠️ **Warning**: Forced failover may result in data loss for 
uncommitted transactions.
 
### Step 4: Verify Failover Success
```sql
-- Run on new primary (db-prod-03)
SELECT 
    replica_server_name,
    role_desc
FROM sys.dm_hadr_availability_replica_states ars
JOIN sys.availability_replicas ar 
    ON ars.replica_id = ar.replica_id;
```
**Expected**: db-prod-03 shows role_desc = PRIMARY
 
### Step 5: Update DNS (if required)
```powershell
# If AG listener didn't handle automatically:
# Update DNS record for prod-db.company.com to 10.1.1.10
# Contact: network-team@company.com
```
 
### Step 6: Verify Application Connectivity
- [ ] Application health check: https://app.company.com/health
- [ ] Run test transaction through application
- [ ] Check application logs for database connection errors
 
### Step 7: Post-Failover Tasks
- [ ] Notify stakeholders of successful failover
- [ ] Update status page
- [ ] Schedule failback (if this was planned maintenance)
- [ ] Document any issues in incident ticket
 
## Rollback Procedure
If failover fails or causes issues:
 
1. If old primary is available:
   ```sql
   ALTER AVAILABILITY GROUP [ProdAG] FAILOVER;
   ```
2. If old primary is unavailable: Restore from backup (see DR-RESTORE-001)
 
## Escalation
- Database Team Lead: John Smith (+1-555-0100)
- On-call DBA: Via PagerDuty
- VP Infrastructure: Jane Doe (+1-555-0101) - for extended outage
 
## Related Documents
- DR-RESTORE-001: Full Database Restore Procedure
- DR-NETWORK-001: Network Failover Procedure
- BACKUP-RESTORE-001: Backup Verification
 
---
*Last Updated: 2024-01-10 after DR drill*
*Next Review: 2024-04-10*

The Runbook Test

A good runbook should be executable by someone who has never performed the task before. Test this by having a junior team member (or someone from another team) follow the runbook while you observe. Every question they ask reveals a gap in the documentation.

Change Logging and Audit Trails

Change logging records every modification to database systems—configurations, schema changes, data fixes, and deployments. This audit trail is essential for troubleshooting, compliance, and understanding how systems evolved over time.

Change Log Entry Components
Component	Description	Example
Timestamp	When the change was made	2024-01-15 14:30:00 UTC
Who	Person or service making the change	jsmith, deploy-service
What	Description of change	Added index on orders.customer_id
Why	Business/technical justification	Query DB-1234 was causing timeouts
Ticket Reference	Link to change request/ticket	JIRA: DB-1234, CHG-5678
Before State	State before change (if applicable)	No index on customer_id
After State	State after change	Index IX_orders_customer_id created
Rollback Plan	How to revert if needed	DROP INDEX IX_orders_customer_id

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-- SQL Server: Automated change tracking table
 
CREATE TABLE dbo.DatabaseChangeLog (
    ChangeID INT IDENTITY PRIMARY KEY,
    ChangeTimestamp DATETIME2 DEFAULT SYSDATETIME(),
    DatabaseName SYSNAME,
    ChangeType VARCHAR(50),
    ObjectName SYSNAME NULL,
    ChangedBy SYSNAME DEFAULT SUSER_SNAME(),
    ChangeDescription NVARCHAR(MAX),
    TicketReference VARCHAR(100),
    BeforeState NVARCHAR(MAX),
    AfterState NVARCHAR(MAX),
    RollbackScript NVARCHAR(MAX),
    ExecutedScript NVARCHAR(MAX)
);
 
-- DDL Trigger to automatically log schema changes
CREATE TRIGGER LogDatabaseChanges
ON DATABASE
FOR DDL_DATABASE_LEVEL_EVENTS
AS
BEGIN
    SET NOCOUNT ON;
    
    DECLARE @EventData XML = EVENTDATA();
    
    INSERT INTO dbo.DatabaseChangeLog (
        DatabaseName,
        ChangeType,
        ObjectName,
        ChangeDescription,
        ExecutedScript
    )
    VALUES (
        @EventData.value('(/EVENT_INSTANCE/DatabaseName)[1]', 'sysname'),
        @EventData.value('(/EVENT_INSTANCE/EventType)[1]', 'varchar(50)'),
        @EventData.value('(/EVENT_INSTANCE/ObjectName)[1]', 'sysname'),
        'Automated DDL capture',
        @EventData.value('(/EVENT_INSTANCE/TSQLCommand/CommandText)[1]', 'nvarchar(max)')
    );
END;
GO
 
-- Manual change log entry (for non-DDL changes)
INSERT INTO dbo.DatabaseChangeLog (
    DatabaseName,
    ChangeType,
    ObjectName,
    ChangeDescription,
    TicketReference,
    BeforeState,
    AfterState,
    RollbackScript
)
VALUES (
    'OrdersDB',
    'Configuration Change',
    'max_degree_of_parallelism',
    'Increased MAXDOP from 4 to 8 to improve query performance',
    'JIRA: DBA-1234',
    'MAXDOP = 4',
    'MAXDOP = 8',
    'EXEC sp_configure ''max_degree_of_parallelism'', 4; RECONFIGURE;'
);
 
-- Query recent changes
SELECT 
    ChangeTimestamp,
    ChangeType,
    ObjectName,
    ChangedBy,
    ChangeDescription,
    TicketReference
FROM dbo.DatabaseChangeLog
WHERE ChangeTimestamp > DATEADD(DAY, -7, GETDATE())
ORDER BY ChangeTimestamp DESC;

Disaster Recovery Documentation

Disaster recovery documentation is the most critical documentation you'll create—and the most important to get right. During a disaster, stress is high, systems may be unavailable, and there's no time for improvisation.

DR documentation must be:

Complete: Every step documented, including ones that seem obvious
Tested: Verified through regular DR drills
Accessible: Available when primary systems are down (offline copies!)
Current: Updated after every significant infrastructure change

DR Documentation Components

•Recovery Time Objective (RTO) — Maximum acceptable downtime. Drives decisions about DR strategy and resources.
•Recovery Point Objective (RPO) — Maximum acceptable data loss. Drives backup frequency and replication strategy.
•Contact Lists — All stakeholders with multiple contact methods. Keep offline copies.
•System Inventory — All systems to be recovered, in priority order.
•Recovery Procedures — Step-by-step for each system. Include validation steps.
•Vendor Contacts — Support numbers, contract IDs, SLA references.
•Access Credentials — Stored securely but accessible during emergencies (break-glass procedures).
•Communication Templates — Pre-written status updates to avoid composing under pressure.

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# Disaster Recovery Plan: Database Systems
 
## 1. Recovery Objectives
 
| System | RTO | RPO | Priority | Recovery Strategy |
|--------|-----|-----|----------|-------------------|
| OrdersDB | 1 hour | 15 minutes | P1 - Critical | Failover to DR replica |
| UsersDB | 1 hour | 15 minutes | P1 - Critical | Failover to DR replica |
| AnalyticsDB | 24 hours | 24 hours | P3 - Low | Restore from backup |
| ReportingDB | 4 hours | 1 hour | P2 - High | Rebuild from OLTP |
 
## 2. Emergency Contacts
 
### Internal
| Role | Primary | Secondary | Email |
|------|---------|-----------|-------|
| DBA On-Call | PagerDuty | +1-555-0100 | dba@company.com |
| DBA Manager | J. Smith (+1-555-0101) | M. Chen (+1-555-0102) | jsmith@company.com |
| VP Infrastructure | A. Johnson (+1-555-0103) | - | ajohnson@company.com |
| Application Team | PagerDuty | +1-555-0200 | app-team@company.com |
 
### Vendors
| Vendor | Support Number | Contract ID | SLA |
|--------|----------------|-------------|-----|
| Microsoft SQL | 1-800-936-3500 | MSFT-12345 | 1 hour response (Premier) |
| AWS Support | Via Console | - | 15 min response (Enterprise) |
| SAN Vendor | 1-800-555-0300 | SAN-67890 | 4 hour onsite |
 
## 3. Recovery Procedures
 
### Scenario: Complete Primary Datacenter Failure
 
**Assumptions**: 
- DC-EAST is completely unavailable
- DR site (DC-WEST) is operational
- Last synchronization was within RPO
 
**Step 1: Confirm Disaster Status (5 min)**
 
1. Attempt to contact DC-EAST NOC: +1-555-0400
2. Verify inability to access any DC-EAST resources
3. Decision authority: VP Infrastructure or DBA Manager
4. If confirmed, proceed with DR activation
 
**Step 2: Notify Stakeholders (parallel with Step 3)**
 
Send to: Executive-Team, App-Team, NOC, Support
Subject: [DISASTER] Database DR Activation - [TIMESTAMP]
 
```
STATUS: DISASTER RECOVERY IN PROGRESS
 
Impact: All production database services
Cause: Primary datacenter unavailable
Action: Failing over to DR site (DC-WEST)
ETA to Recovery: 60 minutes
 
Next Update: 30 minutes
 
DBA Team Lead: [Name, Phone]
```
 
**Step 3: Activate DR Databases (15 min)**
 
3.1 Connect to DR database server:
    - Server: db-prod-03.internal (DC-WEST)
    - Access: Via DC-WEST jump host (dr-jump.internal)
    - Credentials: See DR Credential Safe (physical binder in DR site)
 
3.2 Check last synchronization state:
    ```sql
    SELECT 
        database_name,
        last_hardened_lsn,
        last_hardened_time,
        DATEDIFF(SECOND, last_hardened_time, GETDATE()) AS lag_seconds
    FROM sys.dm_hadr_database_replica_states
    WHERE is_local = 1;
    ```
    **Document the lag for incident report**
 
3.3 Force failover:
    ```sql
    ALTER AVAILABILITY GROUP [ProdAG] 
    FORCE_FAILOVER_ALLOW_DATA_LOSS;
    ```
    ⚠️ Data since last_hardened_time will be lost
 
3.4 Verify databases are online:
    ```sql
    SELECT name, state_desc FROM sys.databases;
    ```
 
**Step 4: Update Network Routing (10 min)**
 
- Contact Network Team: +1-555-0500
- Request DNS update: prod-db.company.com → 10.1.1.10
- Verify propagation: `nslookup prod-db.company.com`
 
**Step 5: Validate Application Connectivity (15 min)**
 
- [ ] Applications can connect to database
- [ ] Health checks passing
- [ ] Test transactions succeeding
- [ ] Error rates normal in monitoring
 
**Step 6: Communicate Recovery (5 min)**
 
Send to: Executive-Team, App-Team, NOC, Support
Subject: [RECOVERED] Database Services Restored - [TIMESTAMP]
 
```
STATUS: RECOVERY COMPLETE
 
Database services have been restored to DR site.
Data loss (if any): [X seconds of transactions]
 
Monitoring: DBA team is actively monitoring
 
Post-Incident Review: Scheduled for [DATE/TIME]
 
Questions: Contact DBA On-Call
```
 
---
**DR Plan Version**: 2.3
**Last Full DR Test**: 2024-01-10
**Last Update**: 2024-01-11
**Next Scheduled Review**: 2024-04-01

Store DR Docs Offline

If your DR documentation is only accessible through systems that might fail during a disaster, it's useless when you need it most. Maintain printed copies in a physical binder at each site, and have offline copies on personal devices of key personnel.

Documentation Maintenance and Governance

Creating documentation is only half the battle. Keeping it current and useful requires ongoing effort and organizational commitment.

Documentation Maintenance Best Practices

•Version Control Everything — Store documentation in Git. Track changes, enable rollback, see who changed what.
•Include Review Dates — Every document should have 'Last Updated' and 'Review By' dates. Enforce review cycles.
•Assign Document Owners — Each document needs a named owner responsible for keeping it current.
•Update During Changes — Make documentation updates part of the change process, not an afterthought.
•Regular Review Cycles — Schedule quarterly reviews for operational docs, semi-annual for architecture.
•Automate Where Possible — Generate configuration docs from live systems. Extract diagrams from infrastructure-as-code.
•Test Runbooks — Schedule regular execution of runbooks on test systems. Every execution is a test of the documentation.
•Solicit Feedback — Make it easy to report documentation issues. Treat doc bugs like code bugs.

Documentation Review Schedule
Document Type	Review Frequency	Review Includes	Owner
DR Procedures	Quarterly + after changes	Test execution, contact updates	DBA Manager
Architecture Diagrams	Semi-annually + after changes	Accuracy verification	Lead DBA
Operational Runbooks	Quarterly	Test execution, step verification	Document owner
Configuration Docs	After every change	Match against live systems	Change implementer
Security Policies	Annually + after incidents	Compliance review	Security Team + DBAs

The Post-Incident Update

After every incident, update documentation. What information was missing? What steps were unclear? What would have helped? Incidents are expensive lessons—capture the learnings in documentation so you don't pay again.

Summary: Building a Documentation Culture

Documentation is infrastructure. It enables consistent operations, reduces dependency on individuals, accelerates incident response, and preserves institutional knowledge. Investing in documentation pays dividends every time someone needs to understand, operate, or troubleshoot your database systems.

Key Takeaways

•Documentation transforms individual knowledge into organizational capability — What's in someone's head is a liability. What's documented is an asset.
•Different audiences need different documentation — Architecture for strategic planning, runbooks for operations, change logs for troubleshooting.
•Configuration documentation must include 'why' — Settings without rationale become mysterious incantations that no one dares change.
•Runbooks must be prescriptive and tested — Vague guidance fails under pressure. Step-by-step procedures with verification steps succeed.
•Change logs enable troubleshooting and compliance — Every change recorded means faster root cause analysis and audit-ready evidence.
•DR documentation must be tested and accessible offline — When disaster strikes, you need working procedures that you can access.
•Documentation requires ongoing maintenance — Build review cycles and updates into your operational processes.

Module Complete:

Congratulations! You have completed the Maintenance Tasks module. You now understand the essential ongoing activities that keep databases healthy, secure, and performant:

Statistics Updates: Keeping the optimizer informed
Index Maintenance: Preventing fragmentation and bloat
Log Management: Ensuring durability and recoverability
Patching: Keeping systems secure and current
Documentation: Preserving knowledge and enabling consistency

These maintenance activities, performed consistently and skillfully, are what separate amateur database administration from professional database engineering. They're the invisible work that keeps systems running reliably—day after day, year after year.

Module Complete

You have mastered the essential maintenance tasks that define professional database administration. Apply these practices to build robust, reliable, and well-documented database environments that enable your organization's success.