pubkey/rxdb · error · RxError

DB9

DB9

Error message

RxDB Error-Code: DB9. Hint: Error messages are not included in RxDB core to reduce build size. To show the full error messages and to ensure that you do not make any mistakes when using RxDB, use the dev-mode plugin when you are in development mode: https://rxdb.info/dev-mode.html?console=error

What it means

DB9 is thrown when you pass { ignoreDuplicate: true } to createRxDatabase() while the dev-mode plugin is not enabled. The ignoreDuplicate option is a dev-only convenience for hot reloading, so RxDB refuses it in production builds to prevent silently sharing an underlying storage between database instances. Enable the dev-mode plugin to use it during development.

Source

Thrown at src/rx-database.ts:857

    };

    databaseNameKeyUnclosedInstancesSet.add(instancePromiseWithResolvers.promise as any as Promise<RxDatabase>);
    DATABASE_UNCLOSED_INSTANCE_PROMISE_MAP.set(databaseNameKey, databaseNameKeyUnclosedInstancesSet);

    (async () => {
        if (closeDuplicates) {
            await Promise.all(
                closeDuplicatesPromises.map((unclosedInstancePromise) =>
                    unclosedInstancePromise
                        .catch(() => null)
                        .then((instance) => instance && instance.close())
                )
            );
        }

        if (ignoreDuplicate) {
            if (!overwritable.isDevMode()) {
                throw newRxError('DB9', {
                    database: name
                });
            }
        } else {
            // check if combination already used
            throwIfDatabaseNameUsed(name, storage);
        }

        USED_DATABASE_NAMES.add(databaseNameKey);

        const databaseInstanceToken = randomToken(10);
        const storageInstance = await createRxDatabaseStorageInstance<
            Internals,
            InstanceCreationOptions
        >(
            databaseInstanceToken,
            storage,
            name,

View on GitHub (pinned to af6fb65f94)

Solutions

1. Remove ignoreDuplicate from createRxDatabase options in production code.
2. If it is dev-only tooling, register the dev-mode plugin: addRxPlugin(RxDBDevModePlugin) when process.env.NODE_ENV !== 'production'.
3. Reuse a singleton database instance instead of relying on ignoreDuplicate.

Example fix

// before
const db = await createRxDatabase({ name: 'mydb', storage, ignoreDuplicate: true });
// after
import { RxDBDevModePlugin } from 'rxdb/plugins/dev-mode';
if (process.env.NODE_ENV !== 'production') {
  addRxPlugin(RxDBDevModePlugin);
}
const db = await createRxDatabase({
  name: 'mydb',
  storage,
  ...(process.env.NODE_ENV !== 'production' ? { ignoreDuplicate: true } : {})
});

import { RxDBDevModePlugin } from 'rxdb/plugins/dev-mode';
import { addRxPlugin } from 'rxdb';
const isDev = process.env.NODE_ENV !== 'production';
if (isDev) addRxPlugin(RxDBDevModePlugin);
if (!isDev && options.ignoreDuplicate) {
  throw new Error('ignoreDuplicate is only allowed in dev mode');
}

function isIgnoreDuplicateAllowed(isDevMode, options) {
  return !options.ignoreDuplicate || isDevMode === true;
}

try {
  db = await createRxDatabase(options);
} catch (err) {
  if (String(err?.code) === 'DB9') {
    // ignoreDuplicate without dev-mode plugin: drop the option and retry
    const { ignoreDuplicate, ...rest } = options;
    db = await createRxDatabase(rest);
  } else {
    throw err;
  }
}

When it happens

Trigger: Calling createRxDatabase({ name, storage, ignoreDuplicate: true }) without adding the dev-mode plugin via addRxPlugin(RxDBDevModePlugin), or with it enabled only conditionally in a production build.

Common situations: Copy-pasting hot-reload example code into a production build; toggling dev-mode plugin per environment so production hits this path; forgetting to register RxDBDevModePlugin after adding ignoreDuplicate.

Related errors

• DB14
• DB3
• DB8
• DOC1
• DOC2

AI-assisted analysis of pubkey/rxdb@af6fb65f94 (2026-08-31). Data as JSON: /api/errors/3d14319a64adc989. Report an issue: GitHub.