Cause: Failed to allocate an extent of the required number of blocks
for an index segment in the tablespace indicated.
Action: Use ALTER TABLESPACE ADD DATAFILE statement to add one or more
files to the tablespace indicated.
The reason you are getting this error is because your tablespace ran
out of space where the index resides.
SELECT TABLESPACE NAME FROM USER_INDEXES
WHERE INDEX_NAME = '&INDEX_NAME';
-- provide the index_name that is failing to get extent allocation
Based on the tablespace named from the top,
ALTER TABLESPACE <tablespace_name_from_above_query>
ADD DATAFILE 'full directory path within quotes with a file name'
SIZE <a reasonable size in MBs denoted with the letter M>
(like 50000M)
Addition: Please make sure that you have free space within your
partition or filesystem.