claude-memory/graph/fixes/fix-batch-pitchingcardratings-lookup-in-pitcher-sort-paper-d-e014f5.md

id	type	title	tags	importance	confidence	created	updated	relations
e014f59b-60ff-4602-91bc-076b3a73f0e8	fix	Fix: batch PitchingCardRatings lookup in pitcher sort (paper-dynasty-database #19)	paper-dynasty-database python peewee pandas performance fix n+1-queries	0.65	0.8	2026-03-03T23:04:16.395675+00:00	2026-03-04T02:04:45.819294+00:00	target type direction strength edge_id 6ebf27b5-c1eb-4e4d-b12a-62e7fdbc9406 RELATED_TO outgoing 0.7 0bcc341f-f60d-4e48-afd0-ddb45d9452b5 target type direction strength edge_id 0fdd32ea-6b6a-4cd0-aa4b-117184e0c81d RELATED_TO outgoing 0.7 d53ccdea-72f2-4342-8cc0-fb2b2c0eb056 target type direction strength edge_id b9375a89-6e0f-4722-bca7-f1cd655de81a RELATED_TO outgoing 0.7 e496d0d4-b7fb-4c61-8738-2a86da490803 target type direction strength edge_id d5795833-cc47-4ee7-a03b-8eda906597d5 RELATED_TO incoming 0.77 f05df710-e8a1-422e-897c-d58c02e984e3

Problem

sort_pitchers() and sort_starters() in app/routers_v2/teams.py called PitchingCardRatings.get_or_none() twice per row inside a DataFrame.apply() — once for vs_hand="L" and once for "R". With 30 pitchers this was 60 queries.

Solution

Before the apply, batch-fetch all ratings for all card IDs in one query and build a (pitchingcard_id, vs_hand) → rating dict. The closure does O(1) dict lookups.

card_ids = pitcher_df["id"].tolist()
ratings_map = {
    (r.pitchingcard_id, r.vs_hand): r
    for r in PitchingCardRatings.select().where(
        (PitchingCardRatings.pitchingcard_id << card_ids)
        & (PitchingCardRatings.vs_hand << ["L", "R"])
    )
}

def get_total_ops(df_data):
    vlval = ratings_map.get((df_data["id"], "L"))
    vrval = ratings_map.get((df_data["id"], "R"))
    ...

Files Changed

• app/routers_v2/teams.py — both sort_pitchers and nested sort_starters

Pattern

General pattern for Peewee + pandas: never do model lookups inside DataFrame.apply. Batch fetch with model << id_list, build a dict, use dict lookup in the closure.