apache/pinot

Pinot can't skip creating derived column when configured in transform functions

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#7,627 opened on Oct 25, 2021

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Description

When reloading segments, pinot will skip many segments when derived column not configured in schema or segments metadata , which will cause some segments not synced latest new columns

We got the following error message when query from table: image

Code need remove:

for (String argument : arguments) {
  ColumnMetadata columnMetadata = _segmentMetadata.getColumnMetadataFor(argument);
  if (columnMetadata == null) {
    LOGGER.warn("Skip creating derived column: {} because argument: {} does not exist in the segment", column,
        argument);
    return false;
  }
  argumentsMetadata.add(columnMetadata);
}

Contributor guide

Research direction
Locate the loop in the code that checks column metadata when creating derived columns and remove it. Then verify that segments reload without skipping when derived column is not configured.
Tech stack
java
Domain
backenddatabase
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
JavaGit
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
75