AWS DynamoDB Flashcards
What type of database is DynamoDB
It is a key/value store, but it, not 100% true as the value can be more complex like JSON.
Can you have a secondary index?
Yes
Is DynamoDB deployed to a server or cluster?
No, it is a managed service from AWS you consume it as a service and scaling is performed automatically by AWS
Is DynamoDB a NoSQL database?
Yes, it is a NoSQL database.
Can I have joines in DynamoDB?
No, this database is a NoSQL key-value/document DB
Is DynamoDB encrypted by default for data at rest?
Yes
Is DynamoDB a schemaless database?
Yes unlike SQL thereis schemes, DynamoDSB is not.
Can I use my own customer managed key?
Yes you can use CMK
What does one read capacity unit represent?
It represents on strong consistent read or two eventual consistent reads, per 4K read. If you read over 4K then dynamoDB will consume one or more read unity.
What is a table in DynamoDB?
It a collection of items
What is an item in DynamoDB?
It is a uniquely identifiable collection of attributes.
What is an attribute in DynamoDB
Each items is composed of one or more attributes with atribute been a PersonID, LastName, FirstName.
Is a primary key on an attribute?
No, th eprimary key is on the item, this is a unique idenifier.
Can I create a backup of a DynamoDB table?
Yes, in the console, API or CLI.
You can restore from the backup.
When restoring from a DynamoDB backup, can I restore to the same table?
Yes, enter same table name for the restore
When restoring from a DynamoDB backup, can I restore to a different table?
Enter a different table name
With DynamoDB can I reserve storage capacity?
No as with storage you pay for only what you use as you use it.
I have a consistent known number of read/write capacity units I use 24/7/365, what can I do to save on cost?
I can purchase reserved capacity for both read and write, this can be for 1 - 3 years.
When you delete a table, are backups automatically deleted?
No.
Are DynamoDB tables encrypted at rest by default?
Yes, but you have the option to switch off encryption.
What is the default read and write capacity units?
5 x 5
Is DynamoDB handled at a database with a collection of tables or individual tables?
Individual tables, for example, when you want to copy all tables belong to your app, you have to do it per table. All configs are per table.
When you perform a write to DynamoDB, is the data written to another AZ?
Yes, in fact, it is written to a min of 3AZ.
When I preform a eventual consistant read on DynamoDB, am i geeteting the last write to the DB table?
No, reading again may give you different result.