[ORC-992] Reached max repeat length, we can directly decide to use DELTA encoding

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.8.0
• Fix Version/s: 1.8.0
• Component/s: Java
• Assignee: Yiqun Zhang
• Reporter: Yiqun Zhang
• Created: 14/Sep/21 05:38
• Updated: 03/Sep/22 22:43
• Resolved: 21/Sep/21 20:38

Description

Reached max repeat length, we can directly decide to use DELTA encoding.
RunLengthIntegerWriterV2.java 756-760

          // if fixed runs reached max repeat length then write values
          if (fixedRunLength == MAX_SCOPE) {
            determineEncoding();
            writeValues();
          }

If fixed runs reached max repeat length. We have been able to determine the use of the DELTA code, fixedDelta is zero.

The computeZigZagLiterals, zzBits100p, and determine isFixedDelta within the determineEncoding method are all redundant in the current case.

Similar practices.
RunLengthIntegerWriterV2.java 767-775

          if (fixedRunLength >= MIN_REPEAT) {
            if (fixedRunLength <= MAX_SHORT_REPEAT_LENGTH) {
              encoding = EncodingType.SHORT_REPEAT;
            } else {
              encoding = EncodingType.DELTA;
              isFixedDelta = true;
            }
            writeValues();
          }

Issue Links

• links to: GitHub Pull Request #907