---
title: "Oracle to Oracle migration guide"
description: "Convert an Oracle export from SQL Developer or SQLcl into an Oracle script with the same tables, keys, indexes and data, and every rule the converter applies."
canonical: https://intosql.com/docs/migrations/oracle-to-oracle
last_updated: 2026-10-15
---

# Oracle to Oracle migration guide

IntoSQL reads the `.sql` file SQL Developer's Database Export or SQLcl writes, with DBMS_METADATA's table definitions and `Insert into` statements, and turns it into one Oracle script with the same tables, columns, keys, indexes, foreign keys, defaults, counters and rows. It evaluates what those exports write for values: `to_date` and `to_timestamp` with their format, `TO_CLOB` and `HEXTORAW` pieces, decimal commas from German or Spanish sessions. Every value Oracle can't hold as it is, and every object it doesn't carry, is listed in the report. The script loads on Oracle 19c and later.

**Convert in the browser:** [Oracle to Oracle](/oracle-to-oracle) opens the converter set up for this pair.

## Export for the best result

In SQL Developer, choose Tools, Database Export, with DDL and the Insert data format, as one file. SQLcl writes the same data with `SET SQLFORMAT INSERT`. Before exporting, set a date format that keeps the time and the century:

```sql
ALTER SESSION SET NLS_DATE_FORMAT = 'SYYYY-MM-DD HH24:MI:SS';
ALTER SESSION SET NLS_TIMESTAMP_FORMAT = 'SYYYY-MM-DD HH24:MI:SS.FF9';
```

- The default format, `DD-MON-RR`, writes each date without its time and with two digits of the year; the report says so (`oracle_date_format`) and each date is read as its day, between 1950 and 2049.
- A `.dmp` file from `exp` or `expdp` is binary. Import it into an Oracle database, Oracle Database Free runs in Docker, and export it with SQL Developer; the converter says so when it gets one (`dump_oracle_binary`).
- Every test export comes from Oracle 21c and 23ai, in American, German and ISO sessions, and is compared with its source cell by cell.

## Convert

In the browser, open [Oracle to Oracle](/oracle-to-oracle) or the converter on the home page, drop the export and choose Oracle. It reads the file from your disk in pieces, twice, and writes the script as it goes, so the file is never uploaded and its size isn't limited by memory. The [desktop app](/docs/desktop) does the same with the file on disk.

With the [command line](/docs/cli):

```shell
intosql inspect shop.sql
intosql convert shop.sql --to oracle --output shop.oracle.sql --report shop.report.json
```

`inspect` lists the tables, their rows and what won't be converted, without writing anything. `convert` writes the script and, with `--report`, the report as JSON.

Through the [API](/docs/api), an export converts like any other file: open a conversion with its name and `"output": {"dialect": "oracle"}`.

## Load into Oracle

```shell
NLS_LANG=.AL32UTF8 sqlplus -S -L shop@//localhost/FREEPDB1 @shop.oracle.sql
```

The script keeps Oracle's own types as the export declared them: `NUMBER` with its precision, `DATE`, `TIMESTAMP`, intervals, `CHAR` and `VARCHAR2` with their `BYTE` or `CHAR` lengths, `RAW` and the LOBs. `XMLTYPE` and `JSON` keep their text in a `CLOB`, so the same script loads on 19c. Storage clauses, tablespaces and the schema prefix are left out, so the tables are created in the schema of the user who runs it.

## What isn't converted

Views, packages, procedures, functions, triggers other than one that fills a column from a sequence, types and synonyms are written in PL/SQL. They are listed in the report by kind and name, never dropped silently, so you can recreate them in Oracle.


## Data types

[Oracle data types between versions](/docs/types/oracle-to-oracle) lists each type that changes in the script: what it becomes, why, and the report line.

## Every other rule

Generated from the engine, where each rule is decided.

| In the dump | In the script | Why | Report line |
| --- | --- | --- | --- |
| collations that ignore case (BINARY_CI) | exact comparison | Column collations aren't written, so a column that ignored case (BINARY_CI) now tells Ana and ana apart. | `case_insensitive_collation` |
| CREATE SEQUENCE | CREATE SEQUENCE with the same options | The export writes where a sequence has reached as its START WITH, so it continues from there. | None |
| virtual columns (GENERATED ALWAYS AS ... VIRTUAL) | virtual columns | The same virtual columns. | `stored_as_virtual` |
| virtual columns with functions IntoSQL doesn't write, and the \|\| operator | a plain column | A formula that can't be written for Oracle leaves a plain column and a report line; the values the export wrote for virtual columns are left out, and Oracle has none to compute. | `generated_not_translated` |
| defaults with functions IntoSQL doesn't write (SYS_GUID(), \|\|) | no default | A default that can't be written is left out and reported. | `default_not_translated` |
| CHECK constraints | translated | The same checks, tested as each row loads. | None |
| CHECK constraints with functions IntoSQL doesn't write | not created | A check that can't be written is left out and reported. | `check_skipped` |
| CHECK constraints that are DISABLE or ENABLE NOVALIDATE | not created | Oracle doesn't apply these checks to the rows already there, so the rows may break them. | `check_not_enforced` |
| function-based, bitmap and domain indexes | not created | IntoSQL writes b-tree indexes on whole columns; create the others again after loading. | `index_skipped` |
| foreign keys | after the data ENABLE NOVALIDATE, then validated with a warning on orphans | The key checks new rows at once and is validated last; rows without a parent leave it unvalidated with a warning instead of stopping the load. | None |
| ON DELETE CASCADE that cascades in a cycle or along a second path | dropped | Oracle's foreign keys act on delete only, with CASCADE or SET NULL. | `foreign_key_action_unsupported` |
| foreign keys to tables the export doesn't create, and DISABLE or NOVALIDATE ones | not created | A key can't name a table that isn't there, and one Oracle doesn't check may have rows without a parent. | `foreign_key_skipped` |
| names longer than Oracle 12.1 allows | shortened | Oracle names hold 128 bytes from 12.2; a longer name is shortened. | `name_shortened` |
| partitioned tables | one table with every partition's rows | The rows are the same; partition the table again in Oracle if it needs it. | `partitions_dropped` |
| several schemas in one export | one schema, tables named after their schema first | The script loads into the schema of the user who runs it, so tables of different schemas get their schema's name in front; an export of one schema keeps its tables' names. | `schemas_merged` |
| NOT NULL columns with values that become NULL | NOT NULL dropped | A column whose values had to become NULL can't keep NOT NULL, or the load would stop. | `not_null_relaxed` |
| views, synonyms, types, packages, procedures, functions and other triggers | listed in the report | Their code is written in PL/SQL, so they are listed for you to recreate. | `not_converted_objects` |
| exports without CREATE TABLE (data only) | types read from the values | A data-only export has only rows, so the types come from the values. | `no_schema` |
| expressions in INSERT values other than the ones exports write | NULL | A converter that doesn't run a database can't evaluate them; to_date, to_timestamp, TO_CLOB, HEXTORAW and the others exports write are read. | `expression_value` |
| text decoded twice (ñ) | copied as it is | The script holds exactly these characters, so they are copied; the report points them out. | `mojibake_suspected` |