perf: locate the q2 zone by name before reading its boundary - #20
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The zone predicate prunes nothing because every row group's z_name statistics span the full name range, so Polars fetched all 1386 MB of boundary geometry to return one 169 KB polygon. Reading the name column alone costs 2.4 MB and identifies the file and row, after which a slice skips every other row group. DuckDB already performs this late materialisation on the same declarative query. SedonaDB and Polars do not.
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The zone predicate prunes nothing because every row group's z_name statistics span the full name range, so Polars fetched all 1386 MB of boundary geometry to return one 169 KB polygon. Reading the name column alone costs 2.4 MB and identifies the file and row, after which a slice skips every other row group.
DuckDB already performs this late materialisation on the same declarative query. SedonaDB and Polars do not.