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When Migrating Schema from Oracle to Postgres, there are few object differences to pay attention to in which one of the object is Identifier.
In Oracle, names of schemas, tables, columns, and functions are automatically converted to uppercase unless they're put inside quotes. But in PostgreSQL, they're converted to lowercase unless they're quoted. As long as you're consistent in how you quote or don't quote these names in your application, everything should work smoothly during migration.
There are few other points related to Identifiers which we have to Pay attention to when migrating from oracle to Postgres such as quoting rules: while both databases use double quotes, PostgreSQL primarily uses them to preserve case, while Oracle uses them for special characters and case sensitivity and maximum identifier length (limited to 30 bytes in Oracle, up to 63 bytes in PostgreSQL).
Identifier handling can affect how applications query tables, call functions, and read schema objects after migration. Small differences in naming behavior can create avoidable runtime issues, especially when code depends on exact case or quoted names.
Understanding these differences early helps teams reduce rework in SQL scripts, ORM mappings, reports, and application queries. It also makes schema conversion more predictable during testing and rollout.
Teams should review naming conventions across schemas, tables, views, columns, indexes, and functions before final migration. It is also important to validate how application queries and integration layers reference those objects in production-like testing.
Early checks can help identify naming mismatches before they become deployment issues. That can save time during cutover and improve confidence in the migrated PostgreSQL environment.