On 12/06/17 12:19, Andres Freund wrote:
> On 2017-12-06 12:14:24 -0500, Tom Lane wrote:
>> Checking out hashint8() on random data shows no such obvious fault.
>> You've apparently got a data set that exposes a weakness in hashint8,
>> but it's not very clear what that is.
>
> It's intentionally designed to cause problems afaict:
>
> http://archives.postgresql.org/message-id/861b9f1f-cdc0-bc49-2595-80bc39c37dc3%40blackducksoftware.com
Definitely not intentionally. My wording there could have been better;
perhaps "we expect to get lots of duplicates in that column and we then
need to find the unique values". Eventually, a substantial number of
the duplicates will be deleted, but that's further along in the process.
-- todd
