[CALCITE-6147] CAST(CAST(EMPNO AS VARCHAR) AS INT) should be simplified to EMPNO

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.36.0
• Fix Version/s: 1.37.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Benchao Li
• Reporter: Benchao Li
• Created: 01/Dec/23 05:08
• Updated: 06/May/24 22:19
• Resolved: 08/Dec/23 05:10

Description

Lossless cast removal has been introduced in CALCITE-3712.

However, VARCHAR's precision is -1, which will not meet the lossless condition in RexUtil

    // 3) From NUMERIC family to CHARACTER family: it depends on the precision/scale
    if (sourceSqlTypeName.getFamily() == SqlTypeFamily.NUMERIC
        && targetSqlTypeName.getFamily() == SqlTypeFamily.CHARACTER) {
      int sourceLength = source.getPrecision() + 1; // include sign
      if (source.getScale() != -1 && source.getScale() != 0) {
        sourceLength += source.getScale() + 1; // include decimal mark
      }
      return target.getPrecision() >= sourceLength; // target.getPrecision() is -1, which will make the optimization fail.
    }

Issue Links

• links to: GitHub Pull Request #3555