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    By David Crowther

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    Question:

    How do you add a Spatial Index to my GIS file in QGIS?

    Answer:

    The Create Spatial Index Tool within QGIS enables you to create spatial indexes very quickly for your GIS Layers. A spatial index can be very important on a GIS layer, especially for large datasets, as they will allow queries to run a lot quicker and speed up map rendering.

    In QGIS I have an input point layer of Lower Super Output Areas – approximately 30,000 records in total!

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    If we view the Shapefile in File Explorer, we can see there are 5 files that make up the GIS Layer…. we are missing a Spatial Index file!

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    From the Processing menu choose > Toolbox > and open the Vector General section.

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    Choose the Create Spatial Index menu option.

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    The Create Spatial Index Tool will open.

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    We will use the following settings:

    • In the Input Layer choose the LSOA Layer.

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    If you now Run the Create Spatial Index Tool, the log file shows that a Spatial Index has been generated.

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    If we view the GIS Layer in File Explorer, there is an additional file type of QIX – which is the Spatial Index for the layer.

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