The direct answer
Track existing connections and the requesting open separately. A blocked request remains pending, while an upgrade event identifies a phase rather than complete application readiness. Require supported connection coordination, an independently established new handle and schema outcome, compatible consumer code and current rights before local use.
Give the requested upgrade its own record
A fictional console stores non-confidential catalogue metadata locally. Document D-A still owns an existing database handle H-A under reviewed schema S-A. A newer document D-B requests the separately reviewed higher schema S-B through opening request Q-B. An “updating database” notice does not identify which handle received an event or whether D-B may use its intended records yet.
This worksheet selects an existing application-owned database and two cooperating trusted documents. It excludes database deletion, new-database creation, forced closure, automatic reload and a data-transformation recipe. H-A, Q-B, H-B and the schema labels are paper associations, not browser objects or version integers.
The ordinary save guide still starts from an already opened database with a reviewed schema. It supplies no upgrade coordination by implication.
Put each event on the right recipient
MDN’s blocked reference says an open connection can block a versionchange transaction on the same database. Its example associates the blocked handler with a later, higher-version opening request.
The versionchange reference describes a structure change requested elsewhere; its example attaches the listener to an existing IDBDatabase result. That is a different recipient from Q-B.
The upgradeneeded reference describes a request to open above the current version and shows schema changes in that opening request’s handler. This identifies a phase, not our application’s complete readiness criterion.
Record these possible observations separately. The worksheet is not a requirement that every upgrade produce a particular three-event trace, nor an implementation of event ordering or handle retirement. Actual request association and complete outcome evidence remain necessary.
Keep connection retirement separate from page compatibility
| Reference | Review question | What is not established |
|---|---|---|
| H-A / D-A | Which existing handle and document own the notification and pending local work? | That every relevant handle has retired. |
| Q-B / D-B | What is the actual opening-request disposition? | That S-B is ready for the application. |
| Upgrade phase | Which admitted schema plan and exact request are associated? | Complete open, data correctness or retained-data safety. |
| H-B / S-B | Is a complete supported handle/schema outcome independently established? | That every loaded page can interpret it. |
| Consumer | Which actual code, current purpose and rights may use the local metadata? | Authority for unrelated work or model disclosure. |
For this application, require a complete inventory of relevant connections and a supported retirement policy before claiming the coordination requirement is met. Closing one visible tab is not the selected inventory criterion. This article supplies no enumeration method, close-completion detector or await-close recipe.
The team must separately establish how pending work is handled without losing data or moving an old operation into a new association. A display label cannot implement that policy. Unknown ownership, incomplete retirement or uncertain earlier outcomes hold admission rather than trigger a destructive recovery.
Define useful readiness more narrowly than a green upgrade notice
The conditional ordinary positive requires independently established H-B/S-B completion, correct retained metadata, compatible actual consumer code, complete supported coordination and current rights. Only that bounded catalogue use becomes eligible. No migration, saved record or usable handle has been observed here.
Schema review needs an explicit approved contract: expected stores and record meanings, permitted changes, required retained information and failure disposition. The event name does not choose those details. The model must not introduce a store deletion, reinterpret old fields or propose wiping drafts simply because the opening request needs an upgrade.
Preserve the original request’s identity during uncertainty. A second request, reset or recreated database must not conceal an unresolved first outcome. Recovery requires its own supported authority and evidence; none is implemented in this worksheet. Keep attempted, pending, failed and independently completed dispositions distinct.
Loaded-document compatibility remains a separate application requirement. The service-worker release guide addresses another lifecycle; it does not supply schema coordination, and this guide does not supply a page reload or worker takeover.
Walk eight inert connection cards
| Invented condition | Proposed disposition |
|---|---|
| 1. Complete coordination, H-B/S-B, data, compatibility and current-rights receipts hold | Conditionally admit only the declared local catalogue use. |
| 2. Q-B reports blocked | Keep its transition pending; request intent is not readiness. |
| 3. H-A receives versionchange | Associate the notice with H-A’s owner and coordination plan. |
| 4. One visible tab closes while other handle ownership is unresolved | No complete retirement conclusion. |
| 5. Q-B reaches upgradeneeded | Record that phase; require the separate complete outcome. |
| 6. A proposal drops stores or erases drafts without an admitted plan | Reject expanded migration or data authority. |
| 7. H-B/S-B fits but an old document or pending operation has unknown compatibility | Withhold that consumer rather than relabel its code or approval. |
| 8. Browser, adapter, association, data outcome or current rights are unknown | Hold the missing prerequisite; no automatic replay or weaker fallback. |
State what the documentation cannot establish
All three opened references displayed modification dates of 26 October 2026. They identify no tested application browser, database, wrapper or migration implementation. Actual full connection inventory, handle lifetime, retirement coordination, complete open and schema outcome, data retention, consumer compatibility and current rights are unimplemented or unknown. Any missing prerequisite blocks real admission.
No database, handle, schema, record, store, transaction, opening request, event, browser, close operation, reload, API or model operation was constructed or run. Only the three declared documentation bodies were read. Boundary remains prelaunch with planned request-path checks; its synthetic policy evidence does not implement this browser-schema coordinator.
Primary sources
Official references supporting the guidance. Examples in this guide are synthetic and are not reports of a production incident.