Returns a new pcpatch containing n consecutive points from a pcpatch, starting at a 1-based index. Use this function to extract a contiguous subset of points from a patch—for example, to sample a large patch in batches or paginate through points.
Syntax
pcpatch ST_range(pcpatch pc, integer start, integer n);Parameters
| Parameter | Description |
|---|---|
pc | The source pcpatch object. |
start | The 1-based index of the first point to include. |
n | The number of points to return, starting from start (inclusive). |
Examples
Update a column to retain only those points:
UPDATE patches SET pa = ST_range(pa, 2, 16);
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