OptionallimitAt most this many features are iterated. Applied to the sorted result
list, so it pages the answer without changing it -- the cursor's
featuresCount still reports the total. Omitted means no cap; 0 yields
nothing.
OptionaloffsetHow many matches to skip before the first one iterated. On an indexed
query the skipped features are never read (the exception is a String
condition, where every candidate has to be read once to be post-filtered
before the list can be paged at all). Defaults to 0.
OptionalsignalCancels the query. Threaded into the actual in-flight reads -- the index traversal and each feature read -- not merely held on this facade, and re-checked between features, so aborting a cursor that has already yielded stops the reads that have not happened yet.
OptionalspatialSpatial filter, answered from the packed Hilbert R-tree:
{ kind: 'bbox', value: [minX, minY, maxX, maxY] },
{ kind: 'point', value: [x, y] }, or
{ kind: 'nearest', value: [x, y] } (at most one feature).
A file with no spatial index throws NoIndex.
OptionalwhereAttribute predicates, each answered from that column's static B+tree and AND-intersected with the others. Matching is EXISTENTIAL over a feature's CityObjects: the feature matches if any one of its objects does. An empty array is treated as no filter at all.
OptionalwholeByte size at or below which a nearest query fetches the WHOLE R-tree in
one read and walks it in memory, instead of streaming a read per node
range. Defaults to WHOLE_INDEX_THRESHOLD (256 KB). Only nearest reads
it. Overridable chiefly so tests can force the streaming path -- every
corpus index is below the default, so without lowering it the best-first
traversal would never execute and the fast path would mask any bug in
it.
What to select. Every field is optional;
select()with no options isselectAll().limit/offsetapply AFTER the search, over the sorted result list -- they page the answer, they do not change it.featuresCounton the returned cursor therefore reports the TOTAL number of matches (or the file's total, for an unfiltered select), regardless of paging.