Re: BUG #14932: SELECT DISTINCT val FROM table gets stuck in aninfinite loop - Mailing list pgsql-bugs

From Todd A. Cook
Subject Re: BUG #14932: SELECT DISTINCT val FROM table gets stuck in aninfinite loop
Date
Msg-id 21d507d9-9024-33a8-37c8-b472b3dce7df@blackducksoftware.com
Whole thread Raw
In response to Re: BUG #14932: SELECT DISTINCT val FROM table gets stuck in aninfinite loop  (Andres Freund <andres@anarazel.de>)
Responses Re: BUG #14932: SELECT DISTINCT val FROM table gets stuck in aninfinite loop  (Andres Freund <andres@anarazel.de>)
List pgsql-bugs
On 12/06/17 16:12, Andres Freund wrote:
> 
>> The datasets I shared are somewhat extreme in the sense that there are
>> many contiguous sequences of hash values, but it only takes one such
>> sequence with at least SH_GROW_MAX_MOVE values to trigger the issue. So
>> the hash table may still be perfectly fine for most keys, and only
>> slightly slower for the keys in the sequence.
> 
> Meh, we're talking about adversarial attacks here.

Hmmmmm...

I found this problem when I dropped 10.1 into a test environment to see
what would happen.  There was no deliberate attempt to break anything.

-- todd


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