Variant subquery forcing table scan via USE INDEX in multi-site resave#4319
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Variant subquery forcing table scan via USE INDEX in multi-site resave#4319lukeholder wants to merge 2 commits into
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Pull request overview
Adjusts VariantQuery’s MySQL USE INDEX (sortOrder…) join hint so it’s only applied for unfiltered “listing” queries, avoiding full table scans when resaving/querying specific variants/products in multi-site setups (issue #4305).
Changes:
- Skip the
elements_ownerssortOrderindex hint whenid,ownerId, orprimaryOwnerIdfilters are present. - Keep the hint for unfiltered queries (and no custom
orderBy) to preserve existing listing performance benefits. - Document the fix in the unreleased changelog.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.
| File | Description |
|---|---|
| src/elements/db/VariantQuery.php | Gates the MySQL USE INDEX (sortOrder…) hint behind a “no specific ID/owner filter” check to prevent forced table scans. |
| CHANGELOG.md | Adds an unreleased entry describing the multi-site resave performance fix. |
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| // Forcing the use of the `sortOrder` index only when listing (no specific element/owner filter), | ||
| // so MySQL doesn't prefer it over targeted indexes when querying by ID. | ||
| $hasSpecificFilter = !empty($this->id) || !empty($this->ownerId) || !empty($this->primaryOwnerId); | ||
| if (Craft::$app->getDb()->getIsMysql() && $sortOrderIndex !== null && empty($this->orderBy) && !$hasSpecificFilter) { |
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Potential fix for #4305.
USE INDEX (idx_...)hint onelements_ownersinVariantQuery::beforePrepare()was being applied unconditionally (for all MySQL queries with no customorderBy), including when resaving a specific product/variant by ID.elementId), but the forcedsortOrderindex causes it to scan the fullelements_ownerstable instead — reported at 1.58M+ rows / ~5s per variant in a multi-site setup.id,ownerId, orprimaryOwnerIdis set, leaving MySQL free to choose the right index for filtered queries while still benefiting from the hint during unfiltered listing queries.Test plan
./craft resave/products --elementId X) in a multi-site, multi-store setup and confirm query time drops significantlysortOrderhint)