Amazon DynamoDB

2017/02/27 - Amazon DynamoDB - 2 new api methods

Changes  Time to Live (TTL) is a feature that allows you to define when items in a table expire and can be purged from the database, so that you don't have to track expired data and delete it manually. With TTL enabled on a DynamoDB table, you can set a timestamp for deletion on a per-item basis, allowing you to limit storage usage to only those records that are relevant.

UpdateTimeToLive (new) Link ¶

Specify the lifetime of individual table items. The database automatically removes the item at the expiration of the item. The UpdateTimeToLive method will enable or disable TTL for the specified table. A successful UpdateTimeToLive call returns the current TimeToLiveSpecification ; it may take up to one hour for the change to fully process.

TTL compares the current time in epoch time format to the time stored in the TTL attribute of an item. If the epoch time value stored in the attribute is less than the current time, the item is marked as expired and subsequently deleted.

Note

The epoch time format is the number of seconds elapsed since 12:00:00 AM January 1st, 1970 UTC.

DynamoDB deletes expired items on a best-effort basis to ensure availability of throughput for other data operations.

Warning

DynamoDB typically deletes expired items within two days of expiration. The exact duration within which an item gets deleted after expiration is specific to the nature of the workload. Items that have expired and not been deleted will still show up in reads, queries, and scans.

As items are deleted, they are removed from any Local Secondary Index and Global Secondary Index immediately in the same eventually consistent way as a standard delete operation.

For more information, see Time To Live in the Amazon DynamoDB Developer Guide.

See also: AWS API Documentation

Request Syntax

client.update_time_to_live(
    TableName='string',
    TimeToLiveSpecification={
        'Enabled': True|False,
        'AttributeName': 'string'
    }
)
type TableName

string

param TableName

[REQUIRED]

The name of the table to be configured.

type TimeToLiveSpecification

dict

param TimeToLiveSpecification

[REQUIRED]

Represents the settings used to enable or disable Time to Live for the specified table.

  • Enabled (boolean) -- [REQUIRED]

    Indicates whether Time To Live is to be enabled (true) or disabled (false) on the table.

  • AttributeName (string) -- [REQUIRED]

    The name of the Time to Live attribute used to store the expiration time for items in the table.

rtype

dict

returns

Response Syntax

{
    'TimeToLiveSpecification': {
        'Enabled': True|False,
        'AttributeName': 'string'
    }
}

Response Structure

  • (dict) --

    • TimeToLiveSpecification (dict) --

      Represents the output of an UpdateTimeToLive operation.

      • Enabled (boolean) --

        Indicates whether Time To Live is to be enabled (true) or disabled (false) on the table.

      • AttributeName (string) --

        The name of the Time to Live attribute used to store the expiration time for items in the table.

DescribeTimeToLive (new) Link ¶

Gives a description of the Time to Live (TTL) status on the specified table.

See also: AWS API Documentation

Request Syntax

client.describe_time_to_live(
    TableName='string'
)
type TableName

string

param TableName

[REQUIRED]

The name of the table to be described.

rtype

dict

returns

Response Syntax

{
    'TimeToLiveDescription': {
        'TimeToLiveStatus': 'ENABLING'|'DISABLING'|'ENABLED'|'DISABLED',
        'AttributeName': 'string'
    }
}

Response Structure

  • (dict) --

    • TimeToLiveDescription (dict) --

      • TimeToLiveStatus (string) --

        The Time to Live status for the table.

      • AttributeName (string) --

        The name of the Time to Live attribute for items in the table.