Aleksey Yeschenko commented on CASSANDRA-7622:

[~blerer] and I had a chat, and he had a concern about having to build up the 
whole dataset from scratch on every request, vs. maintaining one that would 
persist between requests. The idea here is to use that model, and 
{{SimpleDataSet}} for simpler, smaller virtual tables where it's not expensive 
to do, and the complexity of adding extra code and hooks to keep the virtual 
table's view up to date is unjustified.

For bigger and more complex virtual tables - think metrics - one would still 
inherit {{AbstractVirtualTable}}, but wouldn't use {{SimpleDataSet}} that the 
simpler virtual tables use, instead providing a custom implementation, that 
would be more akin to Benjamin's original {{MapBasedSystemView}}. In fact, it's 
likely that we'll take at least a portion of that code to implement {{DataSet}} 
for use in the table metrics virtual table.

> Implement virtual tables
> ------------------------
>                 Key: CASSANDRA-7622
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-7622
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: CQL
>            Reporter: Tupshin Harper
>            Assignee: Chris Lohfink
>            Priority: Major
>             Fix For: 4.0
>         Attachments: screenshot-1.png
> There are a variety of reasons to want virtual tables, which would be any 
> table that would be backed by an API, rather than data explicitly managed and 
> stored as sstables.
> One possible use case would be to expose JMX data through CQL as a 
> resurrection of CASSANDRA-3527.
> Another is a more general framework to implement the ability to expose yaml 
> configuration information. So it would be an alternate approach to 
> A possible implementation would be in terms of CASSANDRA-7443, but I am not 
> presupposing.

This message was sent by Atlassian JIRA

To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org
For additional commands, e-mail: commits-h...@cassandra.apache.org

Reply via email to