{"id":677,"date":"2017-10-23T01:33:12","date_gmt":"2017-10-23T01:33:12","guid":{"rendered":"http:\/\/wiki.thomasandsofia.com\/?p=677"},"modified":"2017-10-23T01:33:34","modified_gmt":"2017-10-23T01:33:34","slug":"databases-summary","status":"publish","type":"post","link":"https:\/\/wiki.thomasandsofia.com\/?p=677","title":{"rendered":"Databases &#8211; Summary"},"content":{"rendered":"<p>https:\/\/www.udemy.com\/aws-certified-solutions-architect-associate\/learn\/v4\/t\/lecture\/2050800?start=0<\/p>\n<h2>Exam Tips<\/h2>\n<ul>\n<li>RDS\n<ul>\n<li>Used for OLTP (Online Transaction Processing)<\/li>\n<li>SQL Server<\/li>\n<li>MySQL<\/li>\n<li>PostgreSQL<\/li>\n<li>Oracle<\/li>\n<li>Aurora<\/li>\n<li>MariaDB<\/li>\n<li><\/li>\n<\/ul>\n<\/li>\n<li>DynamoDB\n<ul>\n<li>No-SQL<\/li>\n<\/ul>\n<\/li>\n<li>RedShift\n<ul>\n<li>\u00a0OLAP<\/li>\n<li>\u00a0Data Warehousing<\/li>\n<\/ul>\n<\/li>\n<li>ElastiCache\n<ul>\n<li>In Memory Caching<\/li>\n<li>Memcached<\/li>\n<li>Redis<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2>What is RDS Multi-AZ<\/h2>\n<ul>\n<li>Used for HA \/ DR<\/li>\n<li>Automatically sychronized to alternate AZ when enabled.<\/li>\n<li>DNS automatically transferred to alternate instance if the primary fails.\n<ul>\n<li>Can simulate a failover by rebooting the primary instance.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2>What is RDS Read\u00a0 Replica<\/h2>\n<ul>\n<li>Used for Read Scaling<\/li>\n<li>Read Replicas cannot be written to unless promoted to their own DB\n<ul>\n<li>Doing this breaks all syncronization between it and the original primary DB.<\/li>\n<\/ul>\n<\/li>\n<li>Can create read replicas of read replicas, but be careful for latency issues.<\/li>\n<\/ul>\n<h2>Aurora<\/h2>\n<ul>\n<li>2 copies of your data in each AZ, with a minimum of 3 AZs.\u00a0 This means 6 copies of your data.\n<ul>\n<li>Can handle the loss of up to 2 copies without affecting write capability.<\/li>\n<li>Can handle the loss of up to 3 copies without affecting read capability.<\/li>\n<li>Storage is &#8216;self healing&#8217;.\u00a0 Data blocks and disks are continuously scanned for errors and repaired automatically.<\/li>\n<\/ul>\n<\/li>\n<li>2 Types of replics are available.\n<ul>\n<li>Aurora Replicas (up to 15)<\/li>\n<li>MySQL Read Replicas (up to 5)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2>DynamoDB<\/h2>\n<ul>\n<li>Push button scaling, meaning you can scale your database on the fly without any downtime.\n<ul>\n<li>You cannot do this with RDS or Aurora. You need to provision a larger instance type or add replicas.<\/li>\n<\/ul>\n<\/li>\n<li>Stored on SSD storage<\/li>\n<li>Spread across 3 geographically distinct data centers.<\/li>\n<li>Read Consistency\n<ul>\n<li>Eventual Consistent Reads (Default)<\/li>\n<li>Strongly Consistent Reads (Guaranteed latency &lt; 1 second)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2>RedShift<\/h2>\n<ul>\n<li>Single Mode (160Gb)<\/li>\n<li>Multi-Node\n<ul>\n<li>Leader Node (manages client connections and receive queries)<\/li>\n<li>Compute Nodes (store data and perform queries and computations)\n<ul>\n<li>Up to 128 compute nodes<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2>ElastiCache<\/h2>\n<ul>\n<li>Caches common queries to reduce load on DB server for data that\n<ul>\n<li>is frequently accessed<\/li>\n<li>does not often change.<\/li>\n<\/ul>\n<\/li>\n<li>Two supported caching engines\n<ul>\n<li>Memcached\n<ul>\n<li>Magento uses this<\/li>\n<\/ul>\n<\/li>\n<li>Redis<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2>Quiz Questions<\/h2>\n<ol>\n<li>Which AWS DB platform is most suitable for OLTP?<\/li>\n<\/ol>\n<p>( ) ElastiCache<br \/>\n(*) RDS\/DynamoDB<br \/>\n( ) RedShift<\/p>\n<p>2) When replicating data from your primary RDS instance to your secondary RDS instance, what is the charge?<\/p>\n<p>( ) Double the standard data transfer charge.<br \/>\n( ) Same as the standard data transfer charge.<br \/>\n(*) No charge, it&#8217;s free.<br \/>\n( ) Half the standard data transfer charge<\/p>\n<p>3) What AWS service is best suited for non-relational databases<\/p>\n<p>( ) RDS<br \/>\n( ) RedShift<br \/>\n(*) DynamoDB<br \/>\n( ) ElastiCache<\/p>\n<p>4) When you add a rule to an RDS security group, you do not need to specify a port number o rprotocol.<\/p>\n<p>( ) True<br \/>\n(*) False<\/p>\n<p>5) If you are using RDSProvisioned IOPS storage with MySQL and Oracle database engines, what is the maximum size RDS volume you can have by default?<\/p>\n<p>( ) 500GB<br \/>\n( ) 1TB<br \/>\n( ) 3TB<br \/>\n( ) 5TB<br \/>\n(*) 6TB<\/p>\n<p>6) What happens to the I\/O operations while you take a database snapshot<\/p>\n<p>(*) I\/O operations are suspended for the duration of the snapshot<br \/>\n( ) Nothing<br \/>\n( ) I\/O operations are sent to the Replica (if available) for the duration of the snapshot.<br \/>\n( ) I\/O operations will be functioning normally.<\/p>\n<p>7) Which AWS service is best used for Business Intelligence Tools\/Data Warehousing?<\/p>\n<p>( ) Elastic Beanstalk<br \/>\n( ) Elasticache<br \/>\n( ) DynamoDB<br \/>\n(*) Redshift<\/p>\n<p>8) In RDS when using multiple availability zones, can you use the secondary database as an independent read node?<\/p>\n<p>(*) No<br \/>\n( ) Only in US-West-1<br \/>\n( ) Depends on how you set it up<br \/>\n( ) Yes<\/p>\n<p>9) Amazon&#8217;s ElastiCache uses which two engines?<\/p>\n<p>( ) Redis &amp; Memory<br \/>\n( ) Redis &amp; Memcrush<br \/>\n(*) Redis &amp; Memcached<br \/>\n( ) MyISAM &amp; InnoDB<\/p>\n<p>10) By Default, the maximum provisioned IOPS capacity on an Oracle and MySQL RDS instance (using Provisioned IOPS) is 30,000 IOPS.<\/p>\n<p>(*) True<br \/>\n( ) False<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>https:\/\/www.udemy.com\/aws-certified-solutions-architect-associate\/learn\/v4\/t\/lecture\/2050800?start=0 Exam Tips RDS Used for OLTP (Online Transaction Processing) SQL Server MySQL PostgreSQL Oracle Aurora MariaDB DynamoDB No-SQL RedShift \u00a0OLAP \u00a0Data Warehousing ElastiCache In Memory Caching Memcached Redis What is RDS Multi-AZ Used for HA \/ DR Automatically sychronized to alternate AZ when enabled. DNS automatically transferred to alternate instance if the primary fails. ..<\/p>\n<div class=\"clear-fix\"><\/div>\n<p><a href=\"https:\/\/wiki.thomasandsofia.com\/?p=677\" title=\"read more...\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[18,20],"tags":[],"class_list":["post-677","post","type-post","status-publish","format-standard","hentry","category-amazon-web-services-aws","category-aws-databases"],"_links":{"self":[{"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=\/wp\/v2\/posts\/677","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=677"}],"version-history":[{"count":1,"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=\/wp\/v2\/posts\/677\/revisions"}],"predecessor-version":[{"id":678,"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=\/wp\/v2\/posts\/677\/revisions\/678"}],"wp:attachment":[{"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=677"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=677"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=677"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}