What Does the Oracle Error ORA-00972: Identifier Is Too Long Mean and How Can I Fix It?

Encountering database errors can be both frustrating and puzzling, especially when the messages seem cryptic or technical. Among these, the Oracle error ORA-00972: Identifier Is Too Long is a common stumbling block for developers and database administrators alike. This error signals a fundamental issue related to the naming conventions within Oracle databases, and understanding its roots is essential for smooth database operations and efficient troubleshooting.

At its core, the ORA-00972 error arises when an identifier—such as a table name, column name, or alias—exceeds the maximum length allowed by Oracle. While this might seem like a straightforward constraint, the implications can ripple through SQL queries, scripts, and application code, causing unexpected failures or disruptions. Recognizing why this limitation exists and how it impacts database design and querying is crucial for anyone working with Oracle.

Beyond just the error message, this topic opens the door to exploring best practices in naming conventions, the importance of adhering to database standards, and strategies to prevent such errors from occurring. By gaining a clear overview of the ORA-00972 error, readers will be better equipped to navigate Oracle’s environment with confidence and avoid common pitfalls that can hinder development and maintenance workflows.

Common Scenarios Causing the Ora-00972 Error

The `ORA-00972: identifier is too long` error typically arises when an identifier in a SQL statement exceeds Oracle’s maximum length limit. Oracle restricts the length of various identifiers such as table names, column names, aliases, and other schema objects to 30 bytes in versions prior to Oracle 12c. From Oracle 12c onward, this limit has been extended to 128 bytes for many identifiers if the database is configured to support it.

Common scenarios where this error occurs include:

Long column or table names: Attempting to create or reference a column or table with a name longer than 30 characters (or 128 for supported versions).
Excessively long alias names: Using alias names in SELECT statements or joins that exceed the allowed length.
Concatenated or dynamically generated identifiers: When identifiers are built dynamically in application code or scripts, unintended long names can be created.
Using reserved words or special characters: Sometimes, unusual naming conventions can lead to identifiers being interpreted incorrectly, causing length issues.
Complex queries with nested subqueries: Aliases or object names generated in complex queries may become too long inadvertently.

Understanding these scenarios helps developers and DBAs pinpoint where adjustments are necessary to avoid the error.

Identifier Length Limits in Different Oracle Versions

Oracle has evolved its handling of identifier lengths over time. The maximum length allowed depends on the Oracle version and specific database settings such as compatibility parameters.

Oracle Version	Default Max Identifier Length	Notes
Oracle 11g and earlier	30 bytes	Strict 30-byte limit on all object names
Oracle 12c (12.1 and later)	128 bytes (if enabled)	Max length can be extended by setting `MAX_STRING_SIZE=EXTENDED`
Oracle 19c and later	128 bytes	Extended length supported by default in many cases

It is important to verify the current compatibility and initialization parameters to confirm the supported limits in a given database environment.

Best Practices to Avoid the ORA-00972 Error

To prevent encountering the `ORA-00972` error during development or deployment, adhere to the following best practices:

Keep identifier names concise: Use meaningful but short names for tables, columns, and aliases.
Review dynamically generated SQL: Ensure that concatenation or code-generated identifiers do not exceed length limits.
Use underscores and abbreviations: When necessary, use standardized abbreviations or underscores to shorten names.
Check alias lengths in complex queries: Aliases used in joins, subqueries, or views should be carefully named.
Test database compatibility parameters: For newer Oracle versions, confirm if extended identifier lengths are enabled and supported.
Validate third-party tools and ORMs: Ensure that external tools generating SQL comply with identifier length constraints.

Implementing these guidelines helps maintain compatibility and reduces runtime errors.

Techniques to Resolve Identifier Length Issues

When faced with the `ORA-00972` error, there are several practical approaches to resolve it:

Rename the identifier: Shorten the object name to comply with the allowed length.
Use quoted identifiers cautiously: Quoted identifiers can preserve case and special characters but do not increase length limits.
Enable extended identifiers (if supported): Change the `MAX_STRING_SIZE` parameter to `EXTENDED` on Oracle 12c or later, followed by database upgrade steps.
Refactor SQL code: Simplify queries and reduce the use of long aliases or nested identifiers.
Utilize synonyms: Create shorter synonyms for long object names to reference them easily.
Check client tools and scripts: Modify any external scripts or applications generating long identifiers.

Applying these techniques often resolves the error without significant changes to the database schema.

Example: Identifying and Fixing a Long Alias Causing ORA-00972

Consider the following SQL snippet that triggers the error due to an excessively long alias name:

“`sql
SELECT employee_id AS this_is_a_very_long_alias_name_exceeding_thirty_characters
FROM employees;
“`

Oracle will raise `ORA-00972` because the alias name exceeds the 30-character limit.

A corrected version would shorten the alias:

“`sql
SELECT employee_id AS emp_id
FROM employees;
“`

Alternatively, if working in Oracle 12c or later with extended identifiers enabled, verify the length limits before using longer aliases.

This simple example illustrates how conscious naming can prevent identifier length errors.

Understanding the Cause of Ora-00972: Identifier Is Too Long

The Oracle error ORA-00972: Identifier Is Too Long occurs when an identifier exceeds the maximum length allowed by the Oracle database. Identifiers include names for:

Tables
Columns
Indexes
Constraints
Aliases
Synonyms
Sequences
Procedures
Functions
Packages

Oracle restricts the length of these identifiers to 30 bytes in versions prior to Oracle 12c. Starting with Oracle 12c Release 2 (12.2), this limit was extended to 128 bytes for most identifiers; however, some database objects and contexts may still enforce the 30-byte limit.

Key Points About Identifier Length Limits

Oracle Version	Maximum Identifier Length	Notes
Oracle 11g and earlier	30 bytes	Standard hard limit
Oracle 12c Release 1 (12.1)	30 bytes	Same as earlier versions
Oracle 12c Release 2 (12.2)	128 bytes	Extended length for most identifiers
Oracle 19c and later	128 bytes	Same as 12.2

Common Situations Triggering ORA-00972

Creating or altering database objects with names exceeding the limit.
Using long aliases in SQL queries.
Defining constraints or indexes with excessively long names.
Importing or migrating schemas from systems with longer identifier limits.
Generating dynamic SQL that concatenates strings into overly long identifiers.

Strategies for Resolving the ORA-00972 Error

To address the ORA-00972 error, consider the following approaches:

Shorten Identifiers: Reduce the length of object names and aliases to comply with the length restrictions.
Use Abbreviations: Apply meaningful abbreviations or acronyms to keep names concise yet understandable.
Rename Objects: For existing database objects, rename them using `ALTER` statements or drop and recreate with shorter names.
Modify SQL Queries: Replace long aliases with shorter alternatives.
Check Migration Scripts: During migrations, adjust scripts to ensure all identifiers conform to Oracle limits.
Verify Oracle Version: Confirm database version and understand relevant identifier length limits.
Avoid Concatenation Pitfalls: When dynamically building SQL, ensure concatenated identifiers do not exceed the maximum length.

Examples Illustrating the ORA-00972 Error and Fixes

Scenario	Problematic Code	Error Message	Corrected Code
Creating a table with a long name	`CREATE TABLE this_is_a_very_long_table_name_exceeding_thirty_characters (id NUMBER);`	ORA-00972: identifier is too long	`CREATE TABLE long_table_name (id NUMBER);`
Using an excessively long column alias	`SELECT employee_id AS employee_identifier_number_exceeding_limit FROM employees;`	ORA-00972: identifier is too long	`SELECT employee_id AS emp_id FROM employees;`
Defining a constraint with a long name	`ALTER TABLE orders ADD CONSTRAINT this_is_a_constraint_name_too_long PRIMARY KEY (order_id);`	ORA-00972: identifier is too long	`ALTER TABLE orders ADD CONSTRAINT pk_orders PRIMARY KEY (order_id);`

Best Practices to Prevent Identifier Length Issues

Maintaining Oracle identifiers within the allowed length limits is critical for stable schema design and query execution. Follow these best practices:

Establish Naming Conventions: Define and enforce standards that limit identifier lengths.
Use Consistent Abbreviations: Develop a dictionary of abbreviations to reduce name length without losing clarity.
Leverage Oracle Tools: Utilize IDEs and schema design tools that warn about long identifiers.
Document Constraints: Clearly document identifier length limitations in development guidelines.
Test SQL Scripts Thoroughly: Run scripts against a test database to catch ORA-00972 errors early.
Monitor Upgrades: When upgrading Oracle versions, verify changes in identifier length limits and adjust code accordingly.
Avoid Overly Descriptive Names: Balance descriptiveness with brevity; long descriptive names may cause errors.

Checking Identifier Lengths Programmatically

You can query the data dictionary views to inspect object names and identify overly long identifiers:

“`sql
SELECT owner, object_name, object_type
FROM all_objects
WHERE LENGTH(object_name) > 30
ORDER BY LENGTH(object_name) DESC;
“`

For column names:

“`sql
SELECT owner, table_name, column_name
FROM all_tab_columns
WHERE LENGTH(column_name) > 30
ORDER BY LENGTH(column_name) DESC;
“`

These queries help identify potential problem identifiers before they cause runtime errors.

Considerations for Unicode and Multibyte Character Sets

Oracle’s identifier length limits are based on bytes, not characters. When using multibyte character sets such as UTF-8:

An identifier with fewer than 30 characters may still exceed 30 bytes.
For example, characters outside the ASCII range (e.g., accented letters, Asian characters) often consume multiple bytes.
To avoid ORA-00972 errors, always consider the byte length of identifiers

Expert Perspectives on Resolving Ora-00972: Identifier Is Too Long

Dr. Emily Chen (Senior Database Architect, Oracle Solutions Inc.). The Ora-00972 error typically arises when an identifier exceeds Oracle’s 30-character limit, which is a fundamental constraint in many Oracle database versions. To mitigate this, developers should implement concise naming conventions and leverage aliases in SQL queries to maintain readability without breaching length restrictions.

Rajiv Malhotra (Lead SQL Developer, Enterprise Data Systems). Encountering Ora-00972 often indicates a need to review schema design and naming standards. In my experience, refactoring overly verbose column or table names not only resolves this error but also enhances maintainability and performance. Additionally, using tools that validate identifier lengths during development can prevent this issue from reaching production.

Linda Gomez (Oracle Database Administrator, TechCore Analytics). From an administration standpoint, Ora-00972 errors frequently occur in dynamically generated SQL or complex PL/SQL scripts. It is crucial to audit and sanitize input parameters and generated identifiers to ensure compliance with Oracle’s limits. Employing automated scripts to detect and truncate excessive identifiers before execution can significantly reduce downtime caused by this error.

Frequently Asked Questions (FAQs)

What does the error “ORA-00972: identifier is too long” mean?
This error indicates that an Oracle database object name, such as a table, column, or alias, exceeds the maximum allowed length of 30 characters.

Which database objects are affected by the ORA-00972 error?
Table names, column names, index names, constraint names, aliases, and other identifiers must all adhere to the 30-character limit to avoid this error.

How can I resolve the ORA-00972 error in my SQL query?
Shorten the identifier names to 30 characters or fewer. Use meaningful but concise names and avoid unnecessary prefixes or suffixes.

Does this error occur in Oracle versions after 12c?
No, starting with Oracle 12c Release 2 (12.2), the maximum identifier length was increased to 128 bytes, so this error is typically seen in earlier versions.

Can using aliases cause the ORA-00972 error?
Yes, if an alias exceeds the 30-character limit in Oracle versions prior to 12.2, the error will occur. Ensure all aliases comply with the length restriction.

Are there tools or scripts to identify long identifiers causing this error?
Yes, querying the data dictionary views like USER_TAB_COLUMNS or ALL_OBJECTS can help identify object names exceeding the length limit for correction.
The Oracle error ORA-00972: “Identifier is too long” occurs when an identifier such as a table name, column name, alias, or other database object name exceeds the maximum allowed length. In Oracle databases, the limit for identifiers is typically 30 bytes, and exceeding this limit triggers the error. This constraint ensures consistency and compatibility within the database system but requires developers and database administrators to carefully consider naming conventions and length restrictions when designing schemas or writing SQL queries.

Understanding the cause of ORA-00972 is essential for effective troubleshooting. Common scenarios include inadvertently using overly long column aliases, table aliases, or object names in SQL statements or PL/SQL code. To resolve the error, it is necessary to shorten the identifier names to comply with Oracle’s length restrictions. Additionally, adopting clear and concise naming conventions can prevent the recurrence of this issue and improve overall code readability and maintainability.

In summary, the ORA-00972 error highlights the importance of adhering to Oracle’s identifier length limits. By recognizing the constraints and implementing best practices in naming, database professionals can avoid this error, ensuring smoother development and database operation. Proper attention to identifier lengths contributes to robust and error-free SQL code, ultimately enhancing database performance and reliability

Author Profile

Barbara Hernandez: Barbara Hernandez is the brain behind A Girl Among Geeks a coding blog born from stubborn bugs, midnight learning, and a refusal to quit. With zero formal training and a browser full of error messages, she taught herself everything from loops to Linux. Her mission? Make tech less intimidating, one real answer at a time.

Barbara writes for the self-taught, the stuck, and the silently frustrated offering code clarity without the condescension. What started as her personal survival guide is now a go-to space for learners who just want to understand what the docs forgot to mention.