Azure Database Services: Choosing the Right Database
Azure

Azure Database Services: Choosing the Right Database

A comprehensive guide to Azure database services, covering SQL Database, Cosmos DB, MySQL, PostgreSQL, and best practices for data management.

March 7, 2024
Technical Writer
5 min read

Azure Database Solutions: A Complete Implementation Guide

Azure offers a comprehensive suite of database services to meet various application needs. This guide helps you choose and implement the right database solution for your requirements.

Database Service Overview

Azure's main database offerings:

ServiceUse CaseKey Features
Azure SQL DatabaseRelational dataManaged SQL Server, scalability
Cosmos DBNoSQL workloadsGlobal distribution, multi-model
MySQL/PostgreSQLOpen sourceManaged services, compatibility
Cache for RedisCachingHigh performance, scalability

Azure SQL Database Implementation

Database Creation

-- Create a new database CREATE DATABASE MyAppDB ( EDITION = 'Standard', SERVICE_OBJECTIVE = 'S1', MAXSIZE = 250GB )

Performance Tier Configuration

{ "name": "MyAppDB", "location": "[resourceGroup().location]", "sku": { "name": "Standard", "tier": "Standard", "capacity": 10 }, "properties": { "collation": "SQL_Latin1_General_CP1_CI_AS", "maxSizeBytes": "268435456000", "zoneRedundant": true, "readScale": "Enabled" } }

Cosmos DB Implementation

Container Creation

const { CosmosClient } = require("@azure/cosmos"); const client = new CosmosClient(connectionString); async function createContainer() { const { database } = await client.databases.createIfNotExists({ id: "MyAppDB" }); const { container } = await database.containers.createIfNotExists({ id: "Items", partitionKey: { paths: ["/category"] }, indexingPolicy: { indexingMode: "consistent", automatic: true, includedPaths: [ { path: "/*" } ], excludedPaths: [ { path: "/description/?" } ] } }); return container; }

Multi-Region Configuration

{ "name": "[variables('accountName')]", "type": "Microsoft.DocumentDB/databaseAccounts", "apiVersion": "2021-04-15", "location": "[parameters('location')]", "kind": "GlobalDocumentDB", "properties": { "consistencyPolicy": { "defaultConsistencyLevel": "Session" }, "locations": [ { "locationName": "East US", "failoverPriority": 0 }, { "locationName": "West US", "failoverPriority": 1 } ], "enableMultipleWriteLocations": true, "enableAutomaticFailover": true } }

Migration Strategies

Database Migration Service

Migration TypeSourceTarget
OfflineSQL ServerAzure SQL
OnlinePostgreSQLAzure PostgreSQL
HybridMongoDBCosmos DB
BulkOracleAzure SQL

Migration Script Example

# Azure Database Migration Service setup $migrationService = New-AzDataMigration ` -ResourceGroupName "MyResourceGroup" ` -Name "MyMigrationService" ` -Location "East US" ` -Sku "Premium_4vCores" # Create migration project $migrationProject = New-AzDataMigrationProject ` -ResourceGroupName "MyResourceGroup" ` -ServiceName "MyMigrationService" ` -ProjectName "MyMigrationProject" ` -Location "East US" ` -SourceType "SQL" ` -TargetType "SQLDB"

Performance Optimization

SQL Database Tuning

-- Create indexes for performance CREATE NONCLUSTERED INDEX IX_OrderDate ON Sales.Orders (OrderDate) INCLUDE (CustomerID, TotalAmount); -- Update statistics UPDATE STATISTICS Sales.Orders WITH FULLSCAN; -- Configure Query Store ALTER DATABASE MyAppDB SET QUERY_STORE = ON ( OPERATION_MODE = READ_WRITE, CLEANUP_POLICY = (STALE_QUERY_THRESHOLD_DAYS = 30), DATA_FLUSH_INTERVAL_SECONDS = 900, MAX_STORAGE_SIZE_MB = 1000 );

Cosmos DB Performance Settings

const containerOptions = { throughput: 400, partitionKey: { paths: ["/id"] }, indexingPolicy: { indexingMode: "consistent", automatic: true, includedPaths: [ { path: "/*", indexes: [ { kind: "Range", dataType: "Number", precision: -1 }, { kind: "Range", dataType: "String", precision: -1 } ] } ] } };

High Availability Configuration

SQL Database Availability Groups

-- Configure Always On availability ALTER AVAILABILITY GROUP [AG_MyAppDB] MODIFY REPLICA ON 'SecondaryNode' WITH (AVAILABILITY_MODE = SYNCHRONOUS_COMMIT); -- Add database to availability group ALTER AVAILABILITY GROUP [AG_MyAppDB] ADD DATABASE MyAppDB;

Cosmos DB Consistency Levels

LevelGuaranteePerformance
StrongLinearizableHighest latency
Bounded StalenessConsistent prefixMedium latency
SessionMonotonic readsLow latency
EventualOut of orderLowest latency

Security Implementation

SQL Database Security

-- Create contained database user CREATE USER AppUser WITH PASSWORD = 'ComplexPassword123!'; -- Grant permissions GRANT SELECT, INSERT, UPDATE, DELETE ON SCHEMA::dbo TO AppUser; -- Enable Row-Level Security CREATE SECURITY POLICY FilterPolicy ADD FILTER PREDICATE dbo.fn_securitypredicate(TenantId) ON dbo.Orders;

Cosmos DB Security

const cosmosKey = await getSecretFromKeyVault("cosmos-key"); const client = new CosmosClient({ endpoint: process.env.COSMOS_ENDPOINT, key: cosmosKey, connectionPolicy: { enableEndpointDiscovery: true, preferredLocations: ["East US", "West US"] } });

Monitoring and Maintenance

Performance Monitoring

# Enable diagnostic settings Set-AzDiagnosticSetting ` -ResourceId $database.Id ` -WorkspaceId $workspaceId ` -Enabled $true ` -Category @("QueryStoreRuntimeStatistics", "Errors") # Set up alerts New-AzMetricAlertRule ` -Name "HighDTU" ` -Location "East US" ` -ResourceGroup "MyResourceGroup" ` -TargetResourceId $database.Id ` -MetricName "dtu_consumption_percent" ` -Operator GreaterThan ` -Threshold 90 ` -WindowSize "00:05:00" ` -TimeAggregationOperator Average

Best Practices Summary

  1. Database Selection

    • Consider workload type
    • Evaluate scaling needs
    • Assess global distribution
    • Review cost implications
  2. Performance

    • Implement proper indexing
    • Use appropriate partitioning
    • Monitor query performance
    • Regular maintenance
  3. Security

    • Enable encryption
    • Implement proper authentication
    • Regular security audits
    • Monitor access patterns
  4. High Availability

    • Configure geo-replication
    • Implement failover groups
    • Regular backup testing
    • Monitor replication lag

Troubleshooting Guide

Common issues and solutions:

  1. Performance Issues

    • Check query plans
    • Review index usage
    • Monitor resource utilization
    • Analyze wait statistics
  2. Connectivity Problems

    • Verify network settings
    • Check firewall rules
    • Review connection strings
    • Monitor timeouts
  3. Replication Issues

    • Check replication status
    • Monitor lag time
    • Verify network connectivity
    • Review error logs

Next Steps

After implementing your database solution:

  1. Set up monitoring and alerting
  2. Implement backup strategies
  3. Configure disaster recovery
  4. Document maintenance procedures
  5. Train database administrators

Remember to regularly review and update your database implementation to maintain optimal performance and reliability.

azure
database
sql
cosmos-db