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Re: Best compaction strategy


This isn’t true if your clustering is time based because the read path can selectively include/exclude sstables based on the clustering keys 

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Jeff Jirsa


On Oct 25, 2018, at 12:26 PM, Dor Laor <dor@xxxxxxxxxxxx> wrote:

TWCS is good for time series but if your workload updates the same keys within the TTL it's the wrong strategy.
This diagram is a good rule of the thumb

<image.png>

On Thu, Oct 25, 2018 at 6:28 AM Alexander Dejanovski <alex@xxxxxxxxxxxxxxxxx> wrote:
Hi Raman,

TWCS is the best compaction strategy for TTL data, even if you have different TTLs (set the time window based on your largest TTL, so it would be 1 day in your case).
Enable unchecked tombstone compaction to clear the data with 2 days TTL along the way. This is done by setting :

ALTER TABLE my_table WITH compaction = {'class':'TimeWindowCompactionStrategy', 'unchecked_tombstone_compaction':'true', ...}

If you're running 3.11.1 at least, you can turn on the unsafe_aggressive_sstable_expiration introduced by CASSANDRA-13418

Cheers,

On Thu, Oct 25, 2018 at 2:59 PM raman gugnani <ramangugnani.007@xxxxxxxxx> wrote:
Hi All,

I have one table in which i have some data which has TTL of 2days and some data which has TTL of 60 days. What compaction strategy will suits the most.
  1. LeveledCompactionStrategy (LCS)
  2. SizeTieredCompactionStrategy (STCS) 
  3. TimeWindowCompactionStrategy (TWCS) 

--
Raman Gugnani


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Alexander Dejanovski
France
@alexanderdeja

Consultant
Apache Cassandra Consulting