russell@unturf.com
db29a08762
B&W print-friendly diagrams + tinkerpop-0001 + wave-3 proof sections. Squash of 94 local commits onto remote master.
56 lines
2.3 KiB
Markdown
56 lines
2.3 KiB
Markdown
---
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id: scan-postgresql
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priority: high
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status: unscanned
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created: 2026-03-23
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---
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## Target
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**Repo:** `https://github.com/postgres/postgres`
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**Language:** C
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**Why:** Query planner join graph traversal — linear list scans in path enumeration or join-order search inflate planning time on queries with many joined tables.
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## Scan command
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```bash
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# Shallow clone
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git clone --depth 1 https://github.com/postgres/postgres /tmp/postgresql
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# Submit to unsandbox
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cat > /tmp/scan-postgresql.sh << 'EOF'
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#!/usr/bin/env bash
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set -euo pipefail
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GRAPH_KW="tarjan|strongly.connected|dfs|scc|topolog|topo.sort|cycle|reachab|postorder|dominator|liveness|digraph|shortest.path|path.find"
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MEM="lappend|list_member|listMember|foreach.*list|list_cell|for_each_cell|lcons|list_concat"
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find /tmp/postgresql/src/backend/optimizer -name "*.c" -o -name "*.h" | sort | while read f; do
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graph_lines=$(grep -inE "$GRAPH_KW" "$f" 2>/dev/null | cut -d: -f1 | head -5 || true)
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[ -z "$graph_lines" ] && continue
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while IFS= read -r lineno; do
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s=$(( lineno > 20 ? lineno - 20 : 1 )); e=$(( lineno + 20 ))
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hit=$(sed -n "${s},${e}p" "$f" 2>/dev/null | grep -iE "$MEM" | head -1 | sed 's/^\s*//' || true)
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[ -n "$hit" ] && echo "CANDIDATE\t${f}:${lineno}\t${hit}"
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done <<< "$graph_lines"
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done
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EOF
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export UNSANDBOX_PUBLIC_KEY=unsb-pk-russ-test-isth-best
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export UNSANDBOX_SECRET_KEY=unsb-sk-rk46c-3zvpg-zjf6z-hjrge
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~/git/un-inception/build/un /tmp/scan-postgresql.sh
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```
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## Key files to check
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- `src/backend/optimizer/path/allpaths.c` — Path enumeration for join graph; rel/path list membership
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- `src/backend/optimizer/path/joinpath.c` — Join path construction; inner/outer relation list scans
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- `src/backend/optimizer/plan/planmain.c` — Plan generation; join relation set operations
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- `src/backend/nodes/list.c` — Core List implementation; `list_member` is O(N)
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## Expected pattern
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`list_member(visited, rel)` or equivalent `foreach` loop checking whether a `RelOptInfo` or `Path` node has already been processed, inside `make_rel_from_joinlist` or a similar join-graph enumeration function — O(N) per check producing O(N²) overall.
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## Acceptance criteria
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- [ ] Scan run and results saved to `tools/scan-results/postgresql.txt`
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- [ ] All CANDIDATE hits triaged (confirmed defect or false positive)
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- [ ] If confirmed: defect ticket created in `tools/tickets/defects/`
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