[mapserver-users] How to avoid reading unneeded Features from PostGIS when displaying by map scale ranges?

[Seth G]

Hi Kyle,

Take a look at LAYER SCALETOKEN - https://mapserver.org/mapfile/layer.html#mapfile-layer-scaletoken
and the RFC https://mapserver.org/development/rfc/ms-rfc-86.html#rfc86 

You should be able to add a filter directly to the DATA clause based on the scale that would filter the data directly at source.

Seth
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On Sun, Feb 20, 2022, at 12:59 AM, Kyle Qian wrote:
> Hi, I know that MapServer will determine the CLASS of a Feature based on the expression and scale range when drawing, but what if I want to avoid reading data that is not needed under the current scale? FILTER can filter LAYER data at the same time as spatial query, but do I have to create a separate LAYER for each scale range? 
> Thanks.
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