Could we have 2000 has a constant? Also explaining why 2000?
We also need to truncate when we set the field. e.g. for the editor this is https://github.com/cloudera/hue/blob/master/desktop/libs/notebook/src/notebook/api.py#L335
(might want to do it here explicitely or in the save methode of Document2 model?)

In a comment, could you add reference to the Django bug and when we hit it?
(and add it to the jira description too)

Shouldn't we do it for any DB to not slow down the search anyway?
Then maybe better in the Document2.save method?

Didn't we said we would move this to document2 save method?

Just renaming the constant and adding a comment and looks good!

We only truncate for Oracle, but this is good enough (other fields will be truncated over time via the save method).

Also add: for performance reasons and to avoid searching in huge fields, we also trunctae to a max length

ORACLE_DOCUMENT2_SEARCH_LENGTH --> DOCUMENT2_SEARCH_MAX_LENGTH

?

Add a new line to split the sections?

############################################################
# Searching saved documents in Oracle returns following error:
#   DatabaseError: ORA-06502: PL/SQL: numeric or value error: character string buffer too small
# This is caused by DBMS_LOB.SUBSTR(%s, 4000) in Django framework django/db/backends/oracle/base.py
# Django has a ticket for this issue but unfixed: https://code.djangoproject.com/ticket/11580.
# Buffer size 4000 limit the length of field equals or less than 2000 characters.
#
# For performance reasons and to avoid searching in huge fields, we also trunctae to a max length

trunctae --> truncate