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We host a very large image set using GeoServer's imagemosaic. Our dataset uses two dimensions (time and elevation). All WMS queries work like a charm in less than 200ms (including round trip time) but WCS queries take from 5 to 11 seconds.

Looking into GeoServer's logs I've found that every time a WCS request is processed there are two calls to the database querying for the full list of values of each dimension. This is an example:

2019-03-21 20:57:02,688 DEBUG [geotools.jdbc] - CREATE CONNECTION
2019-03-21 20:57:02,689 DEBUG [geotools.filter] - exporting PropertyName
2019-03-21 20:57:02,689 DEBUG [geotools.jdbc] - SELECT distinct("date") FROM "public"."data"
2019-03-21 20:57:04,496 DEBUG [geotools.jdbc] - CLOSE CONNECTION
2019-03-21 20:57:04,505 DEBUG [geotools.jdbc] - CREATE CONNECTION
2019-03-21 20:57:04,506 DEBUG [geotools.filter] - exporting PropertyName
2019-03-21 20:57:04,506 DEBUG [geotools.jdbc] - SELECT distinct("asset") FROM "public"."data"
2019-03-21 20:57:06,604 DEBUG [geotools.jdbc] - CLOSE CONNECTION

As you might see above, that full table queries take 4 seconds in a best case scenario.

We are making the WCS request using the POST method with this XML for example:

<GetCoverage service="WCS" version="2.0.1">
    <CoverageId>test__images</CoverageId>

    <Format>image/tiff</Format>

    <DimensionTrim>
        <Dimension>Lat</Dimension>
        <TrimLow>-34.677094</TrimLow>
        <TrimHigh>-34.667741</TrimHigh>
    </DimensionTrim>

    <DimensionTrim>
        <Dimension>Long</Dimension>
        <TrimLow>-61.546615</TrimLow>
        <TrimHigh>-61.526359</TrimHigh>
    </DimensionTrim>

    <DimensionSlice>
      <Dimension>elevation</Dimension>
      <SlicePoint>203</SlicePoint>
    </DimensionSlice>

    <DimensionSlice>
      <Dimension>time</Dimension>
      <SlicePoint>2019-03-18T00:00:00Z</SlicePoint>
    </DimensionSlice>

</GetCoverage>

We tried using the GET method also (using subset parameters) but we are observing the same results.

Is there any way we can avoid WCS to make that full table query?

closed as off-topic by Ian Turton Mar 22 at 8:15

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Questions that relate to the business of vendors and product teams, such as licensing, pricing, release dates, submission of bug reports and enhancement requests, etc, are off-topic here and should be directed instead to the official software support teams." – Ian Turton
If this question can be reworded to fit the rules in the help center, please edit the question.

  • This sort of question is best asked on the GeoServer user list – Ian Turton Mar 22 at 8:16
  • Ian I take your recommendation, but yet i don't believe this is off topic. Could you please re-open the question? – luckyshonway Mar 22 at 11:09

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