Re: Reconstructing transaction content after the fact

Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> On 2020-Sep-02, Tom Lane wrote:
>> See VACUUM FREEZE.  You couldn't hide connections immediately after
>> insertion, but if the idea is to sanitize every so often, it'd help.

> Starting with 9.4 which introduced the use of HEAP_XMIN_FROZEN
> combination in infomask to replace rewriting the xmin value proper, the
> Xids will be preserved by freezing, so that won't help.

Ah, right.

> One option to hide the xids might be to recreate the tables every once
> in a while, with something like

Hmm.  Expensive, but if you were willing to make it even more expensive,
you could also defeat the tuple-ordering attacks mentioned upthread:

   CREATE TABLE votes_copy AS SELECT * FROM votes ORDER BY random();


            regards, tom lane