.nornir/assets/thund-pushdown.svg
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<text x="24" y="26" font-weight="700" font-size="16">Typed projection/filter — pushdown into the source scan</text>
<text x="24" y="46" fill="#555" font-size="12">A structured node the planner reads (not opaque SQL): only the needed columns/rows are read off disk.</text>
<!-- wide source (green) -->
<text x="24" y="80" fill="#2f8f4e" font-size="12" font-weight="600">source · parquet/csv (wide)</text>
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<text x="104" y="112" text-anchor="middle" font-weight="600">orders</text>
<text x="104" y="134" text-anchor="middle" fill="#555" font-size="11">id · customer</text>
<text x="104" y="150" text-anchor="middle" fill="#555" font-size="11">amount · note</text>
<text x="104" y="174" text-anchor="middle" fill="#999" font-size="11">6 rows</text>
<text x="104" y="194" text-anchor="middle" fill="#999" font-size="11">4 columns</text>
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<text x="353" y="128" text-anchor="middle" font-weight="600">Flow · typed node</text>
<text x="353" y="150" text-anchor="middle" fill="#555" font-size="12">projection=[customer, amount]</text>
<text x="353" y="168" text-anchor="middle" fill="#555" font-size="12">filter="amount > 100"</text>
<text x="353" y="188" text-anchor="middle" fill="#2b5fb3" font-size="11" font-style="italic">no opaque SQL — introspectable</text>
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<text x="612" y="120" text-anchor="middle" font-weight="700">DataSourceExec</text>
<text x="612" y="142" text-anchor="middle" fill="#555" font-size="11">projection=[customer, amount]</text>
<text x="612" y="160" text-anchor="middle" fill="#555" font-size="11">predicate=amount > 100</text>
<text x="612" y="182" text-anchor="middle" fill="#c26a2b" font-size="11" font-style="italic">id/note never read · rows pruned</text>
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<text x="466" y="142" fill="#c26a2b" font-size="11">lower</text>
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<text x="812" y="134" text-anchor="middle" font-weight="600">output</text>
<text x="812" y="156" text-anchor="middle" fill="#555" font-size="11">[customer, amount]</text>
<text x="812" y="174" text-anchor="middle" fill="#555" font-size="11">2 rows</text>
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<!-- both backends note -->
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<text x="475" y="262" text-anchor="middle" font-weight="600" font-size="13">lowers to BOTH backends</text>
<text x="475" y="282" text-anchor="middle" fill="#555" font-size="12">native: ctx.table(orders).filter(…).select_columns(…) → scan pushdown</text>
<text x="475" y="300" text-anchor="middle" fill="#555" font-size="12">spark: synth_query → "SELECT customer, amount FROM orders WHERE amount > 100"</text>
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