[HIVE-20847] Review of NullScan Code

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.2.0, 4.0.0
• Fix Version/s: 4.0.0-alpha-1
• Component/s: Physical Optimizer
• Flags: Patch
• Assignee: David Mollitor
• Reporter: David Mollitor
• Created: 31/Oct/18 18:49
• Updated: 17/Nov/22 08:55
• Resolved: 26/Jan/19 01:59

Description

What got me looking at this class was the verboseness of some of the logging. I would like to request that we DEBUG the logging since this level of detail means nothing to a cluster admin.

Also... this contains call would be better applied onto a HashSet instead of an ArrayList.

NullScanTaskDispatcher.java

  private void processAlias(MapWork work, Path path, ArrayList<String> aliasesAffected, ArrayList<String> aliases) {
    // the aliases that are allowed to map to a null scan.
    ArrayList<String> allowed = new ArrayList<String>();
    for (String alias : aliasesAffected) {
      if (aliases.contains(alias)) {
        allowed.add(alias);
      }
    }