On 11/20/18 13:00, Tom Lane wrote:
> If the stored XIDs were 64 bits wide, we'd not have to bother with all
> of this mess ... but adding another 64 bits to tuple headers would be
> a painful space cost, not to mention the storage compatibility issues.
People keep saying that. But didn't someone come up with a way to do
this by storing the top 32 bits just once somewhere in the block, rather
than adding 64 bits to every tuple? I can't remember if there was an
email thread.
Maybe some other drawbacks to that approach, but lets at least point out
adding 64 bits to the tuple header isn't the only way to accomplish this.
And the other thread about memory management... if I'm going to start
religious wars, might as well just start them all at once right? ;)
-J
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