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Just like indexing systems in the relational model, DynamoDB demands that any updates to a table be reflected in each of the table's indices. DynamoDB handles this using a service it calls the "log propagator", which subscribes to the replication logs in each node and sends additional Put, Update, and Delete requests to indices as necessary. [30]
Dynamo is a set of techniques that together can form a highly available key-value structured storage system [1] or a distributed data store. [1] It has properties of both databases and distributed hash tables (DHTs).
The required number of bits, m, given n (the number of inserted elements) and a desired false positive probability ε (and assuming the optimal value of k is used) can be computed by substituting the optimal value of k in the probability expression above:
An entity–attribute–value model (EAV) is a data model optimized for the space-efficient storage of sparse—or ad-hoc—property or data values, intended for situations where runtime usage patterns are arbitrary, subject to user variation, or otherwise unforeseeable using a fixed design.
SimpleDB Logo. Amazon SimpleDB is a distributed database written in Erlang [1] by Amazon.com.It is used as a web service in concert with Amazon Elastic Compute Cloud (EC2) and Amazon S3 and is part of Amazon Web Services.
UPDATE table_name SET column_name = value [, column_name = value ... ] [ WHERE condition ] For the UPDATE to be successful, the user must have data manipulation privileges ( UPDATE privilege) on the table or column and the updated value must not conflict with all the applicable constraints (such as primary keys , unique indexes, CHECK ...
A common table expression, or CTE, (in SQL) is a temporary named result set, derived from a simple query and defined within the execution scope of a SELECT, INSERT, UPDATE, or DELETE statement. CTEs can be thought of as alternatives to derived tables ( subquery ), views , and inline user-defined functions.
In computing, a materialized view is a database object that contains the results of a query.For example, it may be a local copy of data located remotely, or may be a subset of the rows and/or columns of a table or join result, or may be a summary using an aggregate function.