[HBASE-15457] [performance] Save-a-seek; hint HFileReader when Scan is a "Get" Scan

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: HFile, Performance
• Assignee: Unassigned
• Reporter: Michael Stack
• Created: 14/Mar/16 18:32
• Updated: 06/Mar/17 23:18

Description

Have the Scan hint the lower-level Reader when its a 'Get' Scan. Reader is currently doing checks for EOF and when time to load next block on each next invocation. Seems easy enough to return null/end-of-scan if a get-scan and the next block is a different row.

Prompted by @daniel pol questions/suggestions over on HBASE-15392; see towards the end.