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[lake/lance] add Flink memory usage note #1909

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luoyuxia merged 3 commits into from
Oct 31, 2025
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[lake/lance] add Flink memory usage note #1909

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add direct memory usage note
xx789633 Oct 30, 2025
6cb4789
nit
xx789633 Oct 30, 2025
1573a64
Update website/docs/streaming-lakehouse/integrate-data-lakes/lance.md
xx789633 Oct 31, 2025
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2 changes: 2 additions & 0 deletions website/docs/streaming-lakehouse/integrate-data-lakes/lance.md
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Expand Up @@ -72,6 +72,8 @@ Additionally, when following the [Start Datalake Tiering Service](maintenance/ti

> **NOTE**: Fluss v0.8 only supports tiering log tables to Lance.

> **NOTE**: The Lance connector leverages Arrow Java library, which operates on off-heap memory. To prevent `java.lang.OutOfMemoryError: Direct buffer memory` error in Flink Task Manager, please increase the value of `taskmanager.memory.task.off-heap.size` in `<FLINK_HOME>/conf/config.yaml` to an appropriate size.
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@luoyuxia luoyuxia Oct 31, 2025

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what's the appropriate size? Any suggestion?

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@xx789633 xx789633 Oct 31, 2025

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I have updated this to a more concrete suggestion.

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@luoyuxia luoyuxia Oct 31, 2025

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what's the appropriate size? Any suggestion?


Then, the datalake tiering service continuously tiers data from Fluss to Lance. The parameter `table.datalake.freshness` controls the frequency that Fluss writes data to Lance tables. By default, the data freshness is 3 minutes.

You can also specify Lance table properties when creating a datalake-enabled Fluss table by using the `lance.` prefix within the Fluss table properties clause.
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