Active-only UNIQUE indexes on user.email + user.username (TIGER-274) - #323
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A plain UNIQUE spans soft-deleted rows, so soft-delete never freed an email/username — a re-signup with a deleted account's address collided on the index. Migration 0053 moves the unique index onto a generated `<col>_active = IF(deleted=0, col, NULL)`: deleted rows become NULL (multiple NULLs allowed) and free the value; live rows stay unique. Real columns + findByEmail/finders unchanged (they already filter deleted=0). The platform-wide convention for unique + soft-deletable columns (TIGER-274); proven on MariaDB 10.5 via the TigerHosting sibling migration. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01ASauLLscjqdsNqBNsx2Typ
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01ASauLLscjqdsNqBNsx2Typ
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What
Migration
0053moves the UNIQUE indexes onuser.emailanduser.usernameonto a generatedactive-only column, so soft-delete frees the value:
Why
A plain
UNIQUE(email)spans soft-deleted (deleted=1) rows too (ARCHITECTURE §7a: "a deleted rowstill holds its unique value"), so soft-deleting a user never freed their email/username — a re-signup
with that address collided on the index (an ugly
core.api.error.general) instead of gracefullyreusing it. MySQL/MariaDB allow multiple NULLs in a unique index, so deleted rows become
NULLanddrop out, while live rows stay unique.
The real
email/usernamecolumns are untouched andTiger_Model_User::findByEmail+ the findersalready filter
deleted=0, so no application code changes.Convention (TIGER-274)
This is the platform-wide pattern for every unique + soft-deletable column. First instances shipped
alongside this:
user.email/user.username(here) and TigerHostinghosting_account.username+hosting_domain.name. TIGER-274 tracks auditing/converting the rest (org slug, CMS/registry slugs, …).Proof
Applied + verified on dev (MariaDB 10.5): a soft-deleted email/username is reusable by a new active
row; a second active duplicate is still refused.
🤖 Generated with Claude Code
https://claude.ai/code/session_01ASauLLscjqdsNqBNsx2Typ