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Function-based index on LOBs?

From: Frank Foss <fozzie_beer_at_hotmail.com>
Date: Wed, 22 Dec 2004 16:51:20 -0800
Message-ID: <32uj46F3p5tmnU1@individual.net>


Oracle 9.2.0.4 on Win2000 Advanced Server

I tried to find the info on Tahiti, but came up short on what Oracle-supplied functions can be used in function-based indexes.

Here's the idea:
We're currently using an in-house application that stores files on the filesystem, and generating SHA1 hashes per file. This checksum is used to check for duplicates.
We're looking at inserting the files in the database instead, as BLOBs. To speed up the search for duplicate/identical files, the SHA1 (or MD5, or RMD160 or other message digests) will be stored in the same record with the file.

Is it possible to create a function-based index that will create the message digest (SHA1/MD5) upon insert of the bytestream?

Does Oracle provide such a digest function? Is it possible to call an external function? ( "openssl dgst -md5 <something>" ) Or just bite the dust and compute the value and insert it ourselves?

Any hints/tips/tricks/pointers to The Fine Manual appreciated Foz Received on Wed Dec 22 2004 - 18:51:20 CST

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