MapInfo Pro

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Contouring creates a seamless table

  • 1.  Contouring creates a seamless table

    Posted 27 days ago
    Hello
    MapInfo Pro Advanced has a great function for creating contours from a terrain model.
    I have just created a lot of contours for the whole of GB.
    Then I noticed that MapInfo had, in fact, created 2 tables and a Seamless table that opens both.
    I wasn't asked if I wanted this and doesn't do it on smaller areas.
    I can't work out how it has split the contours into each table but each one is approx 500MB.

    Is there a threshold when MapInfo decides to create Seamless tables?

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    John Ievers
    CDR Group
    Hope Valley, United Kingdom
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  • 2.  RE: Contouring creates a seamless table

    Posted 21 days ago
    Hi John,

    I haven't seen this behaviour myself but maybe it happens if the output is larger than a single table can handle?

    From memory this is 2 GB for a NATIVE TAB, there is also a maximum number of rows that a table can handle but cant remember what this is.

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    Duri Bradshaw
    Spatial IT Consultant
    Insight GIS
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  • 3.  RE: Contouring creates a seamless table

    Posted 20 days ago
    Hi Duri,
    I thought it may have been that but the combined size is only 1GB and I am set to write new tables in Extended Tab format anyway.
    There must be a trigger for it somewhere. Just curious what it is set at...

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    John Ievers
    CDR Group
    Hope Valley, United Kingdom
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  • 4.  RE: Contouring creates a seamless table

    Employee
    Posted 19 days ago

    Hi John,

    Yes, it's not very good situation to be in. It's hard to predict final output file size it may create, because each contour may have variable number of geometries in it. We do use some calculations to decide whether final output would fit in single file, and while doing it we remain on safer side, so we do not fail operation in the end due to file size limit. Due to this it may have such 'false alarm' cases.

    We wish to improve this situation in future Release/Patch, by providing more flexibility.

    May we know which kind of contour you were generating (Polyline / Polygon), and what is the total number of records finally generated (Total number of records in all the output tabs)?

    Regards,
    mitesh



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    Mitesh Patel
    Knowledge Community Shared Account
    Shelton CT
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  • 5.  RE: Contouring creates a seamless table

    Posted 19 days ago
    Hi Mitesh
    I created contour lines every 50 metres vertical from a 27GB MRR files.
    This resulted in a total of  157,526 records in two tables (52,801 + 104,725).

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    John Ievers
    CDR Group
    Hope Valley, United Kingdom
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  • 6.  RE: Contouring creates a seamless table

    Employee
    Posted 18 days ago

    157,526 contours is not big number to hit threshold, probably its number of geometries (Points in this case) which is triggering splitting.

    Anyways, better to have choice on UI for Seamless Tab / Single NativeX Tab to control this behavior. Looking forward to including this in future Patch/Release.

    Regards,
    mitesh



    ------------------------------
    Mitesh Patel
    Knowledge Community Shared Account
    Shelton CT
    ------------------------------