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Oracle Identity Governance (OIG) Modify ‘max_string_size’ Parameter To "EXTENDED" for Oracle Database (Doc ID 2592007.1)

Last updated on NOVEMBER 15, 2022

Applies to:

Identity Manager - Version and later
Oracle Database - Enterprise Edition - Version and later
Information in this document applies to any platform.


Oracle Database parameter MAX_STRING_SIZE controls the maximum size of VARCHAR2, NVARCHAR2, and RAW data types in SQL.


From Oracle Database 12c onwards, table column(s) length can be modified to greater than 4000 characters when this parameter value is set to EXTENDED.


Allowed values for this parameter are:


    1. Default value.

    2. Means that the length limits for Oracle Database releases prior to Oracle Database 12c apply (for example, 4000 bytes for VARCHAR2 and NVARCHAR2, and 2000 bytes for RAW).


    1. Means that the 32767 byte limit introduced in Oracle Database 12c applies.


Important considerations before modifying parameter to EXTENDED:

  1. The COMPATIBLE initialization parameter must be set to or higher to set MAX_STRING_SIZE = EXTENDED.

  2. Cannot change the value of MAX_STRING_SIZE from EXTENDED to STANDARD.

  1. Database restart is required several times during modification process.


Known ORA- exceptions encountered when modifying the table column(s) length to greater than 4000 characters are:

  1. ORA-30556: either functional or bitmap join index is defined on the column to be modified

  1. ORA-01404: ALTER COLUMN will make an index too large

  1. ORA-01450: maximum key length (6398) exceeded


Following types of function based indexes are not supported when database parameter ‘max_string_size’ is set to EXTENDED:

CREATE INDEX <index_name> ON <table_name>(<column1_name> DESC, <column2_name>);

CREATE INDEX <index_name> ON <table_name>(<column_name> DESC);






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