# X_MIGRATION_CONCURRENT_PARTITIONED

## Means

a concurrent index build names a partitioned table

## Typical cause

Postgres builds no index concurrently on a partitioned parent (SQLSTATE 0A000); a migration ran create index concurrently on one

## Fix

`CREATE INDEX CONCURRENTLY <index>_<partition> ON <partition> (<columns>);` per partition, then `CREATE INDEX <index> ON ONLY <parent> (<columns>);`, then per partition `ALTER INDEX <index> ATTACH PARTITION <index>_<partition>;` — in a `-- transaction: false` migration ([Partitioned tables](/migrations-and-backfills#partitioned-tables))

[Entity and database](/error-codes#entity-and-database)