76 RLS policies rewritten in one migration: the auth.uid() init-plan trap in Supabase
A recent migration revealed that 76 RLS policies in Supabase were inefficiently using the auth.uid() function. This function was being called for each row, leading to performance issues as the data size increased. By wrapping the function in a subquery, the performance was significantly improved, allowing the function to be evaluated only once per query.
- ▪Supabase's RLS policies were found to be inefficient due to the repeated calls of auth.uid() for each row.
- ▪The issue was identified by Supabase's auth_rls_initplan advisor during a pre-deployment check.
- ▪By modifying the policies to wrap auth.uid() in a subquery, the performance improved as the function was evaluated only once per query.
DEV.to (Top) files mainly under programming. We currently carry 4,924 of its stories.
Story provenance
Source · retrieval · rights · ranking — open for full record
inspect →
Story provenance
Attribution is not the same as permission. This drawer separates discovery metadata, excerpts, WeSearch-generated summaries, reuse status, and whether the publisher receives the visit. Nothing here claims a legal grant the publisher has not made.
Record
| Original publisher | DEV.to (Top) |
| Canonical URL | https://dev.to/arvavit/76-rls-policies-rewritten-in-one-migration-the-authuid-init-plan-trap-in-supabase-4hg |
| Publication time | Wed, 20 May 2026 23:48:33 +0000 |
| Retrieval time | 2026-05-21T00:05:03.135Z |
| Last seen | 2026-05-21T00:05:03.135Z |
| Headline source | Publisher (no WeSearch rewrite) |
| Excerpt source | publisher body |
| Excerpt method | First ~120 words (~800 chars) of extracted publisher body, fair-use limited. |
| Summary | WeSearch · cerebras-chat (WeSearch summarizer) |
| Summary source text | contentText |
| Citation coverage | Summary is a WeSearch-generated derivative; primary citation is the original publisher URL. |
| Cluster | cEb_gCd2Vx7m |
| Cluster logic | Grouped by semantic title/content similarity across sources within a rolling window. Same-publisher template collisions are excluded from coverage comparison. |
| Ranking reason | Story pages are not engagement-ranked. Hub feeds use recency, with optional source-diversified chronological ordering (cap consecutive stories per source). No personalized ranking. |
| Publisher visit | Yes — open original |
| Substitutes article? | No — link-out required for full text |
Rights status (four layers)
WeSearch handling by dimension
| Indexing | May the item be indexed (stored, ranked, made findable)? | Allowed |
| Snippet | May a short excerpt of the publisher's text be shown? | Allowed |
| AI summary | May WeSearch generate its own short summary of the article? | Limited |
| Retrieval / RAG | May the content be exposed for third-party retrieval-augmented generation? | Not asserted |
| Model training | May the content be used to train AI models? | Not asserted |
| Commercial reuse | May the content be reused commercially? | Not permitted |
Basis: Derived from the published RSS/Atom feed. Contact: [email protected]. Reviewed: 2026-07-24.
Opening excerpt (first ~120 words) tap to expand
try { if(localStorage) { let currentUser = localStorage.getItem('current_user'); if (currentUser) { currentUser = JSON.parse(currentUser); if (currentUser.id === 3896990) { document.getElementById('article-show-container').classList.add('current-user-is-article-author'); } } } } catch (e) { console.error(e); } Vadym Arnaut Posted on May 20 76 RLS policies rewritten in one migration: the auth.uid() init-plan trap in Supabase #supabase #postgres #performance #webdev TL;DR. If your Supabase RLS policies call auth.uid() directly inside USING(...) or WITH CHECK(...), Postgres re-evaluates the function once per row. Wrap it as (SELECT auth.uid()) and the planner hoists the call to a single init plan that runs once per query. Same logical query, different plan, different cost at scale.
…
Excerpt limited to ~120 words for fair-use compliance. The full article is at DEV.to (Top).
Discussion
0 commentsMore from DEV.to (Top)
