ORA-01658: unable to create INITIAL extent for segment in tablespace

I was getting the following error while trying to create the index.

create index harvey_1647 on harvey_table( id ) tablespace INDEXES;

ERROR at line 1:

ORA-01658: unable to create INITIAL extent for segment in tablespace INDEXES

The message clearly says that oracle is unable to create the INITIAL extent for the segment in the tablespace INDEXES.

This means that the datafile(s) of INDEXES tablespace are unable to extend because the disk(s) are full.

To fix this move the datafile(s) to the disk which have space or add another datafile which is on the disk having space and it will fix the issue straight way.