Databases Flashcards
Amazon Aurora is compatible with? (DB)
MySQL and PostgreSQL
Minimum and maximum size of Aurora
min 10GB max 128 TB
Is Aurora a fully managed service?
Yes
Aurora resiliency
fault-tolerant and self-healing
Aurora replication is on … level
disk level
Aurora is based on? (medium)
ssd
Aurora cluster volume
virtual database storage volume that spans multiple AZs, with each AZ having a copy of the DB cluster data
Aurora cluster structure
Primary DB instance ( supports R/W, 1 in cluster), Aurora Replica ( read-only replicas, connected to the same storage volume, up to 15)
Aurora Endpoints
Cluster(primary db), Reader(lb for read replicas), Custom, Instance(specific isntance)
Aurora Backup
automatic, 1 to 35 days
Aurora cross-region replicas
supported by MySQL
How many copies aurora maintains and where?
6 copies across 3 AZ
Aurora Global Database
spans across multiple regions, 1 region read-write, up to 5 read only
Aurora Global Database RTO/RPO
RTO less than minute, RPO 5 seconds
DocumentDB is
Fully managed document database service
use cases for DocumentDB
content management, user profiles, and real-time big data.
DocumentDB performance
milions of requests per second with miliseconds latency
DocumentDB storage size?
min 10GB max 64 TB
DocumentDB scaling
up to 15 replcas
How many copies DocumentDB maintains and where?
6 copies across 3 AZ
DocumentDB backup/restore
automatic backups, RPO 5 minutes, restore from snapshot local and cross region
DynamoDB is
nosql database, key/value
DynamoDB keep data on..? (medium)
ssd
DynamoDB resilency
higly resilient across AZs and optionally globaly
DynamoDB TTL
Timestamps for automatic delete of items
DynamoDB LSI
alternative view on a table, Local Secondary Indexes, switch secondary key on table
DynamoDB GSI
alternative view on a table, global secondary indexes, switch primary and secondary keys
DynamoDB and DAX
write-through cache fo dynamoDB
DynamoDB Billing
RCU 4KB read, WCU 1 kb read
DynamoDB consistency model
eventually (possibility to read stale data) or strongly consistent (harder to scale)
DynamoDB Stream
captures data modification events in DynamoDB tables
Aurora Serverless
on-demand, autoscaling configuration for Amazon Aurora, scales aurora capacity units from 0 to max
DynamoDB Queries
finds items using PK or SK
DynamoDB Scans
reads every item in a table
DynamoDB Global tables
multi-region, multi-master database, eventually consistent,
ElastiCache
distributed in-memory cache
ElastiCache work with ..?
redis and memcached
ElastiCache use cases
ready heavy workload with low latency requirements, store session data, reduce database workloads
MemoryDB for Redis
in-memory database service for microservices-based applications
MemoryDB for Redis resiliency
data stored across multiple AZ using transactional log
Neptune supports query languages like
Apache TinkerPop Gremlin and W3C’s SPARQL
Neptune use cases
social networking, recommendation engines, Knowledge Graphs, Identity Graphs
Neptune reliability
6 copies across 3 AZ, self healing, asynchronous replication to read replicas
Neptune Streams
complete sequence of change-log entries that record every change made to your graph data
QLDB transactions are?
ACID
Is QLDB serveless?
yes
RDS supported dbs
Aurora, MySQL, MariaDB, PostgreSQL, Oracle, Microsoft SQL Server.
what is managed by RDS?
backups, software patching, automatic failure detection and recovery
RDS HA
Multi-AZ option with synchronous replication
RDS use cases
app requrie relational dm, data is welformed and structured,
RDS storage backend
EBS (gp2 or io1)
What’s the difference between OLAP and OLTP?
OLAP analyze aggregated data
OLTP process database transactions
RDS encryption
RDS at rest using kms, ssl in transit
RDS cross region
not possible with RDS
RDS proxy
sits between app and databases, fully managed, highly available database proxy for rds
Redshift
Petabyte-scale data warehouse, OLAP
Redshift resiliency
single AZ
Redshift Backup
automatic to s3 1to 35 days
Redshift Encryption
always encrypted AES-256
how redshift improve performance?
build in caching
Amazon Redshift Enhanced VPC Routing
Force traffic to run via VPC
Redshift Spectrum vs Athena
serverless engines to query data stored in s3, but if you use redshift use spectrum, spectrum require redis cluster, while athena only s3
RTO vs RPO
Recovery Time Objective (time to recover ) vs Recovery Point Objective( time to last backup)
Redshift Serverless use cases
unpredictable usage patterns, s3 integration for spectrum, ETL
integration with quickSight(powerBI)
Redshift Serverless scaling
Redshift Serverless can scale automatically for unpredictable workload
How DynamobDB can handle increased loads
using application auto Scaling, to increase capacity in response to traffic patterns
Are DynamoDB Streams enabled by default?
No
IAM database authentication
manage database user credential via iam
