"Simple bulk-loading" is a euphemism for "anything but Desktop."
A simple export/import has no impact on spatial fragmentation. Spatial fragmentation
occurs when data is loaded in other than spatial order (usually over time). Imagine
a lightning_strike table that contains all cloud-ground events over a continent for
several years; this table is very likely to be spatially fragmented. Spatial queries will
hit the spatial index, which will quickly determine the rows, and then the database will
effectively need to run a full table scan (possibly multiple times over) fetching the rows
which are randomly distributed across the table. Spatial defragmentation is the process
of using spatial queries or a representative proxy (eg. county FIPS code) to extract data
in other than the orginal order, with the goal of improving spatial query performance.
Of course, while reordering data by a spatial component will improve spatial queries,
it may negatively impact ordering for other queries (e.g. strike_time), so sometimes
compound ordering is necessary to preserve query performance across multiple
attributes.
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