Hi hongying,

looking forward to your unified memory management framework for IoTDB.

On Thu, May 23, 2024 at 12:11 PM Hongyin Zhang <[email protected]> wrote:

> +1, brilliant job! This work allowed me to learn a lot, which laid a solid
> foundation for subsequent system memory control and improved the system's
> robustness in query scenarios.
>
> Best regards,
> Hongyin Zhang
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> At 2024-05-23 11:08:35, "Liao Lanyu" <[email protected]> wrote:
> >Hi,
> >Currently, the IoTDB query engine does not implement memory control at
> the FE (Frontend) stage. In scenarios with massive series queries (e.g.,
> select * from root.**), the query plans generated at the FE stage can
> become excessively large. Roughly estimating, the size of a single
> SeriesScanNode is about 1/2 KB, which means that two million series
> corresponding to two million SeriesScanNodes would occupy 1 GB, posing a
> potential risk of Out-Of-Memory (OOM). In high concurrency scenarios, even
> if a single query plan is not large, the total memory occupied by multiple
> query plans can still lead to OOM.
> >Therefore, it is now desired to introduce memory size control for FE
> query plans within the query engine.
> >The PR is:&nbsp;https://github.com/apache/iotdb/pull/12573
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> >
> >1435078631
> >[email protected]
> >
> >
> >
> >&nbsp;
>

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