fix(client): build fluent API field map lazily and in linear time by Hprogram · Pull Request #29752 · prisma/orm

Hprogram · 2026-07-22T04:46:45Z

Problem

Client-observed latency of fluent-API actions (findUnique, findFirst, create, update, upsert, delete) scales with the number of relation fields the queried model declares, even for trivial queries like findFirst({ select: { id: true } }) — the generated SQL is identical, and query-plan caching doesn't absorb it because the cost sits in the client-side proxy layer, before the cache.

applyFluent builds a field-name→field map on every invocation using an object-spread accumulator inside reduce, making construction O(fields²) — and it runs eagerly on every property access of a fluent-API action, even though the map is only read inside the fluent Proxy's get trap, i.e. only when chaining .relation() off the returned promise. For non-chained calls it is built and discarded.

Changes

Build the map lazily: it is now constructed on first use inside the Proxy get trap, so plain (non-chained) queries skip it entirely
Build it in a single pass (Object.fromEntries) instead of the quadratic reduce-spread

Measurements

300-relation model, warm p50 over 3000 iterations (@prisma/adapter-better-sqlite3, in-memory), before/after applied to the 7.9.0 runtime bundle with a restore round-trip to confirm attribution:

case	before	after
`findFirst({ select: { id: true } })`	1.49–1.51 ms	0.033 ms
`findMany({ take: 1 })` (control — not a fluent action)	0.023 ms	0.024 ms

findMany never paid this cost; after the change findFirst converges to the same level. A CPU profile of the pre-change run attributed ~77% of sampled self-time to the map construction.

Test plan

Functional tests: fluent-api + fluent-api-null suites (js_better_sqlite3) — 84 passed
pnpm --filter @prisma/client build (incl. type declarations)
Prettier clean

CLAassistant · 2026-07-22T04:46:51Z

All committers have signed the CLA.

coderabbitai · 2026-07-22T04:47:19Z

No actionable comments were generated in the recent review. 🎉

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packages/client/src/runtime/core/model/applyFluent.ts

Summary by CodeRabbit

Performance Improvements
- Improved the efficiency of relational property access by generating field lookups only when they’re first needed.
- Preserved existing fluent API behavior while reducing upfront initialization work.

Walkthrough

applyFluent now defers construction of dmmfModelFieldMap instead of creating it during fluent initialization. The proxy getter initializes the map on demand when a relational property is accessed, using Object.fromEntries(...) with nullish-coalescing assignment.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly describes the lazy, linear-time fluent API field map change.
Description check	✅ Passed	The description matches the implemented performance fix and its motivation.
Linked Issues check	✅ Passed	The change addresses `#29745` by deferring map construction and using a single-pass build.
Out of Scope Changes check	✅ Passed	No unrelated changes are evident beyond the fluent map optimization.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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aqrln

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The fluent API field map was rebuilt on every fluent property access (findFirst/findUnique/create/update/upsert/delete) with a reduce that spread the accumulator each step, making it O(n^2) in the number of model fields. The map is only read when the returned promise is actually chained on, so plain queries paid the full cost for nothing. Build the map lazily inside the proxy get trap (only when a relation is chained) and in a single linear pass, so non-chained queries pay zero. Fixes prisma#29745

codspeed-hq · 2026-07-22T12:28:10Z

Merging this PR will degrade performance by 48.31%

⚠️

Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

❌ 1 regressed benchmark
✅ 16 untouched benchmarks
⏩ 30 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	`BASE`	`HEAD`	Efficiency
❌	`compile blog post page (uncached baseline)`	3.2 ms	6.2 ms	-48.31%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

_{Comparing Hprogram:fix/issue-29745-lazy-fluent-field-map (703e4af) with main (7f39413)}

30 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

…isma#29752) ## Problem Closes prisma#29745. Client-observed latency of fluent-API actions (`findUnique`, `findFirst`, `create`, `update`, `upsert`, `delete`) scales with the number of relation fields the queried model declares, even for trivial queries like `findFirst({ select: { id: true } })` — the generated SQL is identical, and query-plan caching doesn't absorb it because the cost sits in the client-side proxy layer, before the cache. `applyFluent` builds a field-name→field map on every invocation using an object-spread accumulator inside `reduce`, making construction O(fields²) — and it runs eagerly on every property access of a fluent-API action, even though the map is only read inside the fluent Proxy's `get` trap, i.e. only when chaining `.relation()` off the returned promise. For non-chained calls it is built and discarded. ## Changes - Build the map lazily: it is now constructed on first use inside the Proxy `get` trap, so plain (non-chained) queries skip it entirely - Build it in a single pass (`Object.fromEntries`) instead of the quadratic reduce-spread ## Measurements 300-relation model, warm p50 over 3000 iterations (`@prisma/adapter-better-sqlite3`, in-memory), before/after applied to the 7.9.0 runtime bundle with a restore round-trip to confirm attribution: | case | before | after | |---|---|---| | `findFirst({ select: { id: true } })` | 1.49–1.51 ms | 0.033 ms | | `findMany({ take: 1 })` (control — not a fluent action) | 0.023 ms | 0.024 ms | `findMany` never paid this cost; after the change `findFirst` converges to the same level. A CPU profile of the pre-change run attributed ~77% of sampled self-time to the map construction. ## Test plan - [x] Functional tests: `fluent-api` + `fluent-api-null` suites (`js_better_sqlite3`) — 84 passed - [x] `pnpm --filter @prisma/client build` (incl. type declarations) - [x] Prettier clean

This PR contains the following updates: | Package | Type | Update | Change | |---|---|---|---| | [@prisma/adapter-pg](https://github.com/prisma/prisma) ([source](https://github.com/prisma/prisma/tree/HEAD/packages/adapter-pg)) | imports | minor | [`7.9.1` -> `7.10.0`](https://renovatebot.com/diffs/npm/@prisma%2fadapter-pg/7.9.1/7.10.0) | | [@prisma/client](https://www.prisma.io) ([source](https://github.com/prisma/prisma/tree/HEAD/packages/client)) | imports | minor | [`7.9.1` -> `7.10.0`](https://renovatebot.com/diffs/npm/@prisma%2fclient/7.9.1/7.10.0) | --- ### Release Notes <details> <summary>prisma/prisma (@prisma/adapter-pg)</summary> ### [`v7.10.0`](https://github.com/prisma/orm/releases/tag/7.10.0) [Compare Source](prisma/orm@7.9.1...7.10.0) ##### Prisma ORM 7.10.0 Prisma ORM 7.10.0 introduces a compatibility package for running Prisma 7 alongside newer Prisma versions, secures Prisma Studio's local server, and includes fixes across Prisma Client and the PostgreSQL, MariaDB, Neon, SQLite, and Prisma Postgres Serverless adapters. ##### Highlights ##### Run Prisma 7 alongside Prisma 8 This release introduces `@prisma/prisma7`, a compatibility package that lets you retain a matching Prisma 7 CLI and configuration while installing Prisma 8 in the same project. Once 7.10.0 is released, a side-by-side installation can use: ```sh npm install --save-dev prisma@8 @prisma/prisma7@7.10.0 npm install @prisma/client@7.10.0 ``` Use `prisma` for the directly installed Prisma 8 CLI and `prisma7` for Prisma 7: ```sh npx prisma --version npx prisma7 --version npx prisma7 generate npx prisma7 migrate dev npx prisma7 db push ``` Prisma 7 now prefers version-specific configuration files, allowing its configuration to coexist with Prisma 8's `prisma.config.*` files: ```ts // prisma7.config.ts import { defineConfig } from '@prisma/prisma7/config' export default defineConfig({ schema: 'prisma/schema.prisma', migrations: { path: 'prisma/migrations', }, }) ``` Without an explicit `--config` option, Prisma 7 searches for: 1. Root-level `prisma7.config.*` files. 2. `.config/prisma7.*` files. 3. Existing `prisma.config.*` files as a backwards-compatible fallback. The supported extensions are `.js`, `.ts`, `.mjs`, `.cjs`, `.mts`, and `.cts`. An explicit config path always takes precedence: ```sh npx prisma7 generate --config ./custom/prisma7.config.ts ``` New projects initialized by the Prisma 7 CLI use `prisma7.config.ts`. Existing projects containing only `prisma.config.*` continue to work without migration or additional warnings. If a `prisma7.config.*` file exists but cannot be loaded, Prisma reports the error rather than silently falling back to another configuration. The `prisma7` identity is carried through CLI help, version output, shell completion, initialization, migration, database, and generation guidance. Stable Prisma concepts such as `schema.prisma`, Prisma Migrate, `@prisma/client`, and `PRISMA_*` environment variables remain unchanged. Together, the separate executable and configuration namespace make it possible to operate Prisma 7 and Prisma 8 side by side without command or config-file collisions. [#29949](prisma/orm#29949), [#29969](prisma/orm#29969), [#29994](prisma/orm#29994), [#30000](prisma/orm#30000), [#30002](prisma/orm#30002), [#30020](prisma/orm#30020) ##### Prisma Studio security hardening Prisma Studio's local HTTP server now: - Binds explicitly to `127.0.0.1` instead of all network interfaces. - Rejects browser requests from origins other than the active `localhost` or `127.0.0.1` Studio URL. - No longer returns wildcard CORS headers. - Applies the same protections across Node.js, Bun, and Deno. This prevents network clients or malicious websites from accessing Studio's database endpoints while Studio is running. [#29890](prisma/orm#29890) ##### Prisma Client - Fixed `P2002` errors from nested writes so `meta.modelName` identifies the model where the unique constraint violation occurred, including models using `@@map` and `@@schema`. [#29628](prisma/orm#29628) - Fixed automatically batched `findUniqueOrThrow()` calls so every missing record rejects with `P2025`; later misses no longer resolve to `undefined`. [#29654](prisma/orm#29654) - Parameter-chunked statements are now executed atomically in a transaction and rolled back if a later chunk fails. [#29771](prisma/orm#29771) - Improved interactive transaction cleanup during `$disconnect()`, including transactions whose driver-level startup is still in progress. [#28768](prisma/orm#28768) - Prevented transaction cleanup failures after a timeout or backend termination from becoming unhandled promise rejections. [#29611](prisma/orm#29611) - Fixed fluent relation queries when relation fields are literally named `select` or `include`. [#29683](prisma/orm#29683) - Fixed handling of `Date` and `Uint8Array` values created in other JavaScript realms, such as iframes, jsdom, and Node.js `vm` contexts. [#29177](prisma/orm#29177) - Invalid `Date` values passed to `$queryRaw` or `$executeRaw` now throw `PrismaClientValidationError` instead of a generic error. [#29718](prisma/orm#29718) - Fixed `moduleFormat` inference for the `prisma-client` generator in TypeScript projects using `module: "node16"` or `"nodenext"`. Generated output now follows the nearest `package.json` `type`, defaulting to CommonJS when absent. [#29712](prisma/orm#29712) - Deserialized `Bytes` values now own standalone `ArrayBuffer`s rather than exposing unrelated contents from Node.js's shared `Buffer` pool. This applies to both regular and raw query results. [#29701](prisma/orm#29701) - Fixed an incorrect logging context in the remote executor, including Accelerate-backed query execution. [#28892](prisma/orm#28892) ##### Client extensions and observability - Result-extension `compute` callbacks now receive the current model name as a typed second argument: ```ts compute(data, modelName) { // ... } ``` The model name is also preserved when multiple extensions compose the same computed field. [#29782](prisma/orm#29782) - Improved OpenTelemetry context for remotely executed queries: - `$on('query')` callbacks run within the matching `db_query` span. - Events from one operation share the same trace. - Error events are recorded as span exceptions. - Log events continue to be emitted when tracing is disabled or their reported span is unavailable. [#28892](prisma/orm#28892) ##### Driver adapters ##### MariaDB - `@prisma/adapter-mariadb` now accepts an existing `mariadb` pool. External pools remain caller-owned unless `disposeExternalPool: true` is supplied. [#27992](prisma/orm#27992) - Fixed pooled connection leaks during commit, rollback, and failed transaction startup. Connections are now returned with `release()` and transaction-specific listeners are removed before reuse. [#29612](prisma/orm#29612) - Added support for bracketed IPv6 addresses in both `mysql://` and `mariadb://` connection strings. [#29026](prisma/orm#29026) - Prevented malformed connection strings from exposing embedded passwords in retained debug output and diagnostic reports. [#27992](prisma/orm#27992) ##### PostgreSQL, Neon, and Prisma Postgres Serverless - PostgreSQL deadlocks using SQLSTATE `40P01` are now reported as `P2034` transaction write conflicts. [#29717](prisma/orm#29717) - PostgreSQL `RESTRICT` violations using SQLSTATE `23001` are now reported as `P2003`, preserving an available field or constraint name. [#29554](prisma/orm#29554) - `@prisma/adapter-pg` now preserves database constraint names when reporting unique constraint violations through `P2002`. [#29587](prisma/orm#29587) - Prisma Postgres Serverless now prefers the named constraint for `P2002`, falling back to parsed field names when no constraint name is available. [#29801](prisma/orm#29801) - Fixed Neon HTTP adapter serialization for typed parameters such as `Bytes` and `DateTime`. [#29747](prisma/orm#29747) ##### SQLite - `@prisma/adapter-better-sqlite3` now converts previously unhandled SQLite result codes into typed database errors instead of exposing raw driver errors. - The complete `SQLITE_BUSY` family is now mapped to socket timeout errors, with numeric extended result codes preserved where available. [#29794](prisma/orm#29794) ##### CLI and Migrate - `prisma generate` can now offer to install Prisma's agent skills. The opt-in prompt: - Is shown at most once per machine. - Is skipped in CI, containers, Git hooks, npm lifecycle scripts, and watch mode. - Is skipped when `--no-hints` is used or Prisma skills are already installed. - Times out after 30 seconds. - Never causes generation to fail if installation is unsuccessful. [#29690](prisma/orm#29690) - A globally installed CLI now warns during `prisma generate` when its version differs from the project's local `prisma` or `@prisma/client`, and recommends running the local CLI. The check is best-effort and does not fail generation. [#29593](prisma/orm#29593) - `prisma version` and `prisma version --json` now include the resolved Prisma CLI package path, making global-versus-local installation issues easier to diagnose. [#29573](prisma/orm#29573) - Empty or generator-only schema files now report `Schema must contain a datasource block` from `db pull`, `db push`, and `migrate dev`, rather than reaching the schema engine and potentially producing inconsistent errors. [#29657](prisma/orm#29657) - CLI commands now tolerate corrupt, unreadable, or unwritable command-state files. Invalid state is reinitialized, writes are atomic, and persistence failures fall back to in-memory state. [#29609](prisma/orm#29609) - Studio now recognizes semicolon-delimited `sqlserver://` connection strings before reporting the existing explicit message that SQL Server is not supported by Studio. [#29623](prisma/orm#29623) - The AI-agent safety checkpoint now also covers interactive `prisma db push` confirmations involving data-loss warnings, rather than only invocations using `--accept-data-loss`. [#29793](prisma/orm#29793) ##### Performance and reliability - Optimized query-plan execution by eagerly evaluating plans with one unconditional database operation and synchronously interpreting the remaining pure plan. Cached plans remain immutable. [#29004](prisma/orm#29004) - Prevented call-stack overflows when rendering very large parameter lists or combining chunked results containing hundreds of thousands of rows. [#29751](prisma/orm#29751) - Reduced ordinary query setup overhead by constructing fluent-relation field maps lazily and in linear time. Non-fluent queries no longer build this map. [#29752](prisma/orm#29752) ##### Dependencies - Updated the transitive `fast-uri` dependency to a patched release addressing production audit advisories affecting versions through `3.1.3`. [#29758](prisma/orm#29758) </details> --- ### Configuration 📅 **Schedule**: (UTC) - Branch creation - At any time (no schedule defined) - Automerge - At any time (no schedule defined) 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about these updates again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Mend Renovate CLI](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.oirnoir.dev/OIRNOIR/YouTube-Helper-Server/pulls/41

coderabbitai Bot approved these changes Jul 22, 2026

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aqrln approved these changes Jul 22, 2026

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dosubot Bot added the lgtm This PR has been approved by a maintainer label Jul 22, 2026

Hprogram force-pushed the fix/issue-29745-lazy-fluent-field-map branch from 8a679a7 to ebcfa35 Compare July 22, 2026 11:35

Merge branch 'main' into fix/issue-29745-lazy-fluent-field-map

703e4af

aqrln merged commit e720bd6 into prisma:main Jul 22, 2026
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fix(client): build fluent API field map lazily and in linear time - #29752

fix(client): build fluent API field map lazily and in linear time#29752
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Hprogram:fix/issue-29745-lazy-fluent-field-map

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Hprogram commented Jul 22, 2026

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Merging this PR will degrade performance by 48.31%

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