Oracle 11g External Tables size limit

Question

Is there a limit for the files that are defined as external tables in Oracle 11g? As per http://download.oracle.com/docs/cd/B19306_01/server.102/b14237/limits002.htm, the last parameter External Tables file - Maximum size, it is Dependent on the operating system.

Does this mean that external tables can be as big as the underlying OS or File System can handle?

Answer 1

Although I haven't been able to find a definitive answer, my feeling is that any file used for an external table can be as big as the OS can handle. You can have mutliple files for each external table definition so your external table can, theoretically at least, be very large, although performance is going to be a limiting factor here. Again there doesn't seem to be a definitive answer to the number of files you can have per external table definition. Here's the link to the 11g limits which are much the same as the 10g page you posted.

Answer 2

Limit on the number of files specified in the LOCATION clause is 32767. Each location is passed out to the access driver as an ODCIArgDesc, the VARRAY ODCIArgDescList has a size of 32767 (do a "describe ODCIArgDescList").

The size of the external files is limited/determined by the OS system calls which access the files and this is OS port dependent. Most modern OS'es support 64 bit file sizes though. Some OS'es may still be stuck with 32 bit files.