[PHOENIX-5969] Read repair reduces the number of rows returned for LIMIT queries

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.0.0, 4.14.3
• Fix Version/s: 4.16.0
• Assignee: Kadir OZDEMIR
• Reporter: Kadir OZDEMIR
• Created: 20/Jun/20 13:19
• Updated: 03/Sep/20 21:42
• Resolved: 03/Aug/20 17:52

Description

Phoenix uses HBase PageFilter to limit the number of rows returned by scans. If a scanned index row is unverified, GlobalIndexChecker repairs this rows. This repair operation leads to either skipping the unverified row or scanning its repaired version. Every scanned row including unverified rows are counted by the page filter. Since unverified rows are counted but not returned for the query, the actual number of rows returned for a LIMIT query becomes less than the set limit (i.e., page size) for the query.

Issue Links

• is cloned by: PHOENIX-6068 (5.x) Read repair reduces the number of rows returned for LIMIT queries
• is part of: PHOENIX-6067 (5.x) Global Secondary Index Parity with 4.x
• links to: PR