Re: Introducing a memory control mechanism during the query planning stage #12573

[William Song]

Hi Lanyu,

Bravo work! Learned a lot from your PR.

Best
Ziyang

> 2024年5月23日 11:08，Liao Lanyu <1435078...@qq.com.INVALID> 写道：
> 
> 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
> 
> 
> 
> 
> 1435078631
> 1435078...@qq.com
> 
> 
> 
> &nbsp;