Subject Re: [firebird-support] Re: detect duplicate blobs, how to?
Author Tim Ward
You are aware of course that you can't use any hashing function on its own to detect duplicates? - the best you can do is detect *probable* duplicates, filtering out ones that are *definitely* different, in order to *reduce*, not eliminate, the amount of work you end up doing comparing byte by byte.

On 09/02/2017 14:39, hamacker sirhamacker@... [firebird-support] wrote:
Well, the man page says fully supports text BLOBs, I assume that binary not.
If HASH() behavior will operate ^Z and others control chars in Blob Image, then now I need to think how to use this function to kill duplications.

Any function like CHECKSUM, CRC32,...?

2017-02-09 10:36 GMT-02:00 Dmitry Yemanov dimitr@... [firebird-support] <>:

09.02.2017 14:48, hamacker wrote:
> There is a HASH function but only for string.

It works for blobs as well.


Tim Ward