# Reference Index

| File | Brief description |
| --- | --- |
| [empty-strings-handling.md](empty-strings-handling.md) | Oracle treats '' as NULL; PostgreSQL keeps empty strings distinct—patterns to align behavior in code, tests, and migrations. |
| [no-data-found-exceptions.md](no-data-found-exceptions.md) | Oracle SELECT INTO raises "no data found"; PostgreSQL doesn’t—add explicit NOT FOUND handling to mirror Oracle behavior. |
| [oracle-parentheses-from-clause.md](oracle-parentheses-from-clause.md) | Oracle allows `FROM(TABLE_NAME)` syntax; PostgreSQL requires `FROM TABLE_NAME`—remove unnecessary parentheses around table names. |
| [oracle-to-postgres-sorting.md](oracle-to-postgres-sorting.md) | How to preserve Oracle-like ordering in PostgreSQL using COLLATE "C" and DISTINCT wrapper patterns. |
| [oracle-to-postgres-to-char-numeric.md](oracle-to-postgres-to-char-numeric.md) | Oracle allows TO_CHAR(numeric) without format; PostgreSQL requires format string—use CAST(numeric AS TEXT) instead. |
| [oracle-to-postgres-type-coercion.md](oracle-to-postgres-type-coercion.md) | PostgreSQL strict type checks vs. Oracle implicit coercion—fix comparison errors by quoting or casting literals. |
| [postgres-union-all-planner.md](postgres-union-all-planner.md) | UNION ALL branches can produce poor plans when predicate pushdown is limited—review plans and split or reshape queries when needed. |
| [postgres-materialized-view-refresh.md](postgres-materialized-view-refresh.md) | Materialized views are not auto-refreshed after base-table changes—application or jobs must explicitly refresh them. |
| [postgres-concurrent-transactions.md](postgres-concurrent-transactions.md) | PostgreSQL allows only one active command per connection—materialize results or use separate connections to avoid concurrent operation errors. |
| [postgres-refcursor-handling.md](postgres-refcursor-handling.md) | Differences in refcursor handling; PostgreSQL requires fetching by cursor name—C# patterns to unwrap and read results. |
| [oracle-to-postgres-timestamp-timezone.md](oracle-to-postgres-timestamp-timezone.md) | CURRENT_TIMESTAMP / NOW() return UTC-normalised timestamptz in PostgreSQL; Npgsql surfaces DateTime.Kind=Unspecified—force UTC at connection open and in application code. |