External Table " IO_OPTIONS " how it helps in performance.
(Doc ID 1337241.1)
Last updated on FEBRUARY 20, 2025
Applies to:
Oracle Database Backup Service - Version N/A and laterOracle Database Exadata Express Cloud Service - Version N/A and later
Oracle Database Cloud Exadata Service - Version N/A and later
Oracle Database Cloud Service - Version N/A and later
Oracle Database - Enterprise Edition - Version 11.1.0.7 and later
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Goal
The goal is to explain the SQL*Loader IO_OPTION option which can be useful for performance while using External table.
The IO_OPTIONS clause allows you to specify I/O options used by the operating system for reading the data files. The only available values are DIRECTIO and NODIRECTIO (the default).
DIRECTIO
If the DIRECTIO option is specified, then an attempt is made to open the data file and read it using direct I/O. If successful, then the operating system and NFS server (if the file is on an NFS server) do not cache the data read from the file. This can improve the read performance for the data file, especially if the file is large. If the DIRECTIO option is not supported for the data file being read, then the file is opened and read but the DIRECTIO option is ignored.
NODIRECTIO
If the NODIRECTIO option is specified or if the IO_OPTIONS clause is not specified at all, then direct I/O is not used to read the data files.
Solution
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