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Posted to issues@drill.apache.org by "Paul Rogers (JIRA)" <ji...@apache.org> on 2018/10/12 05:12:00 UTC
[jira] [Updated] (DRILL-6791) Merge scan projection framework into
master
[ https://issues.apache.org/jira/browse/DRILL-6791?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Paul Rogers updated DRILL-6791:
-------------------------------
Description:
Merge the next set of "result set loader" code into master via a PR. This one covers the "schema projection" mechanism which:
* Handles none (SELECT COUNT\(*)), some (SELECT a, b, x) and all (SELECT *) projection.
* Handles null columns (for projection a column "x" that does not exist in the base table.)
* Handles constant columns as used for file metadata (AKA "implicit" columns).
* Handle schema persistence: the need to reuse the same vectors across different scanners
* Provides a framework for consuming externally-supplied metadata
* Since we don't yet have a way to provide "real" metadata, obtains metadata hints from previous batches and from the projection list (a.b implies that "a" is a map, c[0] implies that "c" is an array, etc.)
* Handles merging the set of data source columns and null columns to create the final output batch.
was:
Merge the next set of "result set loader" code into master via a PR. This one covers the "schema projection" mechanism which:
* Handles none (SELECT COUNT(*)), some (SELECT a, b, x) and all (SELECT *) projection.
* Handles null columns (for projection a column "x" that does not exist in the base table.)
* Handle file metadata (AKA implicit columns)
* Handle schema persistence: the need to reuse the same vectors across different scanners
* Provides a framework for consuming externally-supplied metadata
* Baring "real" metadata, obtains metadata hints from previous batches and from the projection list (a.b implies that "a" is a map, c[0] implies that "c" is an array, etc.)
> Merge scan projection framework into master
> -------------------------------------------
>
> Key: DRILL-6791
> URL: https://issues.apache.org/jira/browse/DRILL-6791
> Project: Apache Drill
> Issue Type: Improvement
> Affects Versions: 1.15.0
> Reporter: Paul Rogers
> Assignee: Paul Rogers
> Priority: Major
>
> Merge the next set of "result set loader" code into master via a PR. This one covers the "schema projection" mechanism which:
> * Handles none (SELECT COUNT\(*)), some (SELECT a, b, x) and all (SELECT *) projection.
> * Handles null columns (for projection a column "x" that does not exist in the base table.)
> * Handles constant columns as used for file metadata (AKA "implicit" columns).
> * Handle schema persistence: the need to reuse the same vectors across different scanners
> * Provides a framework for consuming externally-supplied metadata
> * Since we don't yet have a way to provide "real" metadata, obtains metadata hints from previous batches and from the projection list (a.b implies that "a" is a map, c[0] implies that "c" is an array, etc.)
> * Handles merging the set of data source columns and null columns to create the final output batch.
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