[mapserver-dev] MOTION to adopt RFC 118 - Vendor-specific WMS FILTER param

[Stephen Woodbridge]

On 9/21/2017 12:15 PM, Daniel Morissette wrote:
> On 2017-09-21 1:25 AM, Andrea Peri wrote:
>> Hi,
>>
>> The trick is to have every fields of db indexed
>>
>> Otherwise a remote filter on an not indexed fields could slowly hardly.
>> :)
>>
> 
> Keep in mind that the additional filter does not replace the original 
> filter, but is actually AND'ed to it. So it probably won't be that much 
> worse in general even without indexes on all fields since the extra 
> filter is only applied to those records that were already returned in 
> normal use without the WMS filter param.
> 
> 
And if I'm not mistaken, indexing will only help on the primary record 
selection, like a spatial index, then you have a new record set and that 
record set is not indexed so you then have to cycle through that and 
applied each filter to each record to get the final record set. I think 
this is what Daniel is explaining.

-Steve

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