ORA-01682: read-only DB cannot allocate temporary space in tablespace

[7280]

Hi,
i have a standby database 8.1.7.4 on aix 4.3.3
I opened the db in read only mode because i have to issue a heavy query but while i run it i have this error:
ORA-01682: read-only DB cannot allocate temporary space in tablespace TEMPORAL
This is output of show parameter sort:
nls_sort string
sort_area_retained_size integer 20971520
sort_area_size integer 20971520
sort_multiblock_read_count integer 2
I have a temporal tablespace of 1 GB and it's used 135 mb, so why i'm not able to run the query if i have more than 800 MB in temporary tablespace free.
Also when i run the query i queried v$sort_usage but i see always no rows selected. What's wrong?
Thanks in advance
Tarek

 

[Turkbear]

Since the database needs to write to the temporary
tablespace in order to do sorts ( and other things I imagine) you cannot have it in read-only mode..
If you want to keep others out when you run your query, open the database in restricted mode ...