Database Reference
In-Depth Information
DynamoDB versus S3
DynamoDB and
S3
(short for
Simple Storage Service
) are both storage/database services
provided by Amazon to be exposed to the NoSQL database. S3 is used for wide data stor-
age as it has capacity to store data up to a 5 TB maximum item size, where as DynamoDB
has capacity to store data up to 64 KB, but both have no limit on attributes for a particular
item. S3 creates a bucket that stores data. Buckets are the essential containers in Amazon
S3 for data storage. S3 is for large data storage, which we are rarely going to use. For ex-
ample, data stored for analysis purposes or data stored for the backup and restore proced-
ure. It has a slower response time. DynamoDB is used for high performance. In Dy-
namoDB, we need a key-value data store that can handle thousands of read/write opera-
tions per second.
DynamoDB is a flexible NoSQL database that we use to store small features, metadata, and
index information—in short, data that is more dynamic. In DynamoDB, data retrieval is
very fast because the data is stored on SSDs, and the data is replicated across many servers
that are located in availability zones.
While using S3, we don't need to configure anything to get started. We need a key, and we
can upload the data; it's the way to store data in S3. Now you only need to keep track of the
key we used for a particular application. In DynamoDB, we need to configure a few things,
such as when creating tables, we need to specify the primary key as well as make provision
for the read/write throughput value. S3 doesn't support object locking, but if we need it,
then we have to build it manually, whereas DynamoDB supports optimistic object locking.
Optimistic locking is an approach to ensure that the client-side item that we are updating is
the same as the item in DynamoDB. If we use this approach, then our database writes are
protected from being overwritten by other writes.
One of the good features of S3 is that every S3 object or document that is stored in it has a
web address. By using this web address, a document can be accessed without any impact
on the web server or the database.
S3 uses the eventual consistency model in which, if no new updates are made on a given
data item, all accesses to that item will return the last updated value. DynamoDB follows
eventual consistency and strong consistency, in which all accesses are seen by all parallel
processes, by all parallel nodes, and by all processors in sequential order. DynamoDB
doesn't support spatial data. It can store points and extend it to build a Geohash-based in-
dex that also indexes lines (for example, roads) and areas (for example, boundaries) that
