The ORA-12733 error occurs in Oracle databases when a regular expression exceeds the system's maximum allowed length. This limit is enforced by the REGEXP_LIKE function to prevent memory overflow and performance degradation.

To address this issue, consider the following approaches:

1. Reduce Regular Expression Length: Simplify the expression by breaking it into smaller components or restructuring the query.
2. Adjust Database Configuration: Increase the REGEXP_LIKE_LIMIT parameter using an ALTER SESSION command. For example:

   ALTER SESSION SET REGEXP_LIKE_LIMIT = new_limit_value;
   

   Ensure the new value is within reasonable memory constraints.
3. Optimize Queries: Review SQL queries for alternative methods that avoid lengthy regular expressions, such as using string functions or indexing.
4. Upgrade Hardware Resources: If other methods fail, consider enhancing server hardware or implementing database optimizaton techniques like partitioning.

To check the current REGEXP_LIKE_LIMIT value in Oracle:

• For newer versions (e.g., 12c and above), use:

  SELECT DBMS_METADATA.get_database_attribute(null, 'REGEXP_LIKE_LIMIT') FROM dual;
  

• To session-level limits, query dynamic performance views:

  SELECT resource_name, resource_limit FROM V$SESSION WHERE resource_name = 'REGEXP_LIKE_LIMIT';
  

In Oracle 11g, the DBMS_METADATA.get_database_attribute function may not be available. Alternative methods enclude:

• Query system parameters:

  SELECT name, value FROM v$parameter WHERE name = 'REGEXP_LIKE_LIMIT';
  

• Check resource limits via data dictionary views:

  SELECT resource_name, MAX(resource_limit) FROM dba_resources WHERE resource_name = 'REGEXP_LIKE_LIMIT' GROUP BY resource_name;
  

  Note that dba_resources might not exist in 11g; if unavailable, inspect initialization parameters or configuration files.

If queries return no rows, the parameter might not be explicitly set, defaulting to Oracle's internal limit. In such cases, consult database logs or an administrator for further investigation.