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fix(book): minor nit on tiered compaction

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Signed-off-by: Alex Chi <iskyzh@gmail.com>
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Alex Chi
2025-01-09 17:29:48 -05:00
parent cc1b174515
commit 09196377c5
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mini-lsm-book/src/week2-03-tiered.md
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@@ -147,7 +147,7 @@ The current trigger only reduces space amplification. We will need to add new tr
### Task 1.2: Triggered by Size Ratio
The next trigger is the size ratio trigger. The trigger maintains the size ratio between the tiers. From the first tier, we compute the size of `this tier / sum of all previous tiers`. For the first encountered tier where this value `> (100 + size_ratio) * 100%`, we will compact all previous tiers and the current tier. We only do this compaction with there are more than `min_merge_width` tiers to be merged.
The next trigger is the size ratio trigger. The trigger maintains the size ratio between the tiers. From the first tier, we compute the size of `this tier / sum of all previous tiers`. For the first encountered tier where this value `> (100 + size_ratio) * 100%`, we will compact all previous tiers excluding the current tier. We only do this compaction with there are more than `min_merge_width` tiers to be merged.
For example, given the following LSM state, and assume size_ratio = 1, we should compact when the ratio value > 101%: