Enhanced Full-Text Search makes extensive use of file descriptors when executing searches. With concurrent searches and large text indexes, this may cause a connection to receive this error message:
ERRORMSG, Error (): Available files (-1) less than min 5
This message indicates that the Enhanced Full-Text Search process has run out of file descriptors, based on the limit for the process. If you see this error message, raise the process limit for file descriptors for the Enhanced Full-Text Search process.
max_session_fd limits the number of file descriptors an Enhanced Full-Text Search session can allocate. You can use this in situations where the file descriptors limit cannot be raised.
The max_session_fd defaults to 0, which means that each session is limited only by the Enhanced Full-Text Search process file descriptors limit. The minimum setting for max_session_fd is 5.
If you are seeing the error message above and you cannot raise the file descriptor limit for the Enhanced Full-Text Search, the best way to gauge how to set this parameter is to take the ((max file descriptors) - 20)/(max concurrent connections).
For example, if the file descriptors limit is set to 1024 and the maximum numberof concurrent connections to the Enhanced Full-Text Search is 50:
((1024) - 20)/50 =~ 20
The more available file descriptors to an Enhanced Full-Text Search session, the better.
Because the maximum number of file descriptors that each Enhanced Full-Text Search session uses is being limited, performance may be decreased. Sybase recommends that you use max_session_fd carefully.
You must restart the Enhanced Full-Text Search process for max_session_fd changes to take effect.
