[HBASE-10247] Client promises about timestamps

• Type: Brainstorming
• Status: Closed
• Priority: Minor
• Resolution: Won't Fix
• Assignee: Unassigned
• Reporter: Lars Hofhansl
• Created: 27/Dec/13 07:29
• Updated: 16/Jun/22 17:13
• Resolved: 30/Apr/15 16:26

Description

This is to start a discussion about timestamp promises declared per table of CF.
For example if a client promises only monotonically increasing timestamps (or no custom set timestamps) and VERSIONS=1, we can aggressively and easily remove old versions of the same row/fam/col from the memstore before we flush, just by supplying a comparator that ignores the timestamp (i.e. two KV just differing by TS would be considered equal).
That would increase the performance of counters significantly.

Issue Links

• is related to: HBASE-14070 Hybrid Logical Clocks for HBase
• relates to: HBASE-9905 Enable using seqId as timestamp
• relates to: HBASE-10856 Prep for 1.0