[
https://issues.apache.org/jira/browse/DRILL-7572?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17038913#comment-17038913
]
ASF GitHub Bot commented on DRILL-7572:
---------------------------------------
vvysotskyi commented on issue #1971: DRILL-7572: JSON structure parser
URL: https://github.com/apache/drill/pull/1971#issuecomment-587353797
@paul-rogers, thanks for the explanation, it is great that EVF will handle
such case without additional changes.
Regarding `supportsCountPushDown()`, for Parquet we already have a rule
which replaces scan with a count by the direct scan with the value from the
metadata. The complexity appears when we have count by column. In this case,
only statistics may help. The rule mentioned above is
`ConvertCountToDirectScanPrule`.
The good news is that when Metastore will be supported for other non-parquet
format plugins, it became possible to use its metadata for such optimizations.
By the way, looks like changes for the first CR round weren't pushed.
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
> JSON structure parser
> ---------------------
>
> Key: DRILL-7572
> URL: https://issues.apache.org/jira/browse/DRILL-7572
> Project: Apache Drill
> Issue Type: Improvement
> Affects Versions: 1.18.0
> Reporter: Paul Rogers
> Assignee: Paul Rogers
> Priority: Major
> Fix For: 1.18.0
>
>
> DRILL-6953, PR #1913 provides an EVF-version of the JSON reader. The original
> plan was to commit a first draft, with the feature disabled, then evolve from
> there. Review comments suggested we ensure that the first PR pass all unit
> tests with the feature enabled. Another comment suggested the JSON parser
> portion be reusable for other format or storage plugins. All good ideas.
> The amount of change in the original PR was becoming too large. So, we'll go
> ahead and split the work into smaller portions.
> This ticket is for the "JSON structure parser." This parser accepts the token
> stream from the Jackson parser and provides a framework to create a tree
> structure that describes the data. To keep the code simple, to simplify
> tests, and to make review easier, the structure parser does not directly
> integrate with the rest of Drill. Instead, it provides a number of listener
> interfaces which the next level implements. (The next level will be in
> another PR.)
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
