Re: Query ID Calculation Fix for DISTINCT / ORDER BY and LIMIT / OFFSET

On Tue, 18 Mar 2025 at 21:00, Michael Paquier <michael@paquier.xyz> wrote:
> If we make the whole cheaper with only extra entropy added for NULLs
> in nodes and strings, I'd rather have an insurance policy for the
> custom functions.  Something like that:
> - Forbid a size of 0 in AppendJumble().
> - When dealing with a non-NULL case in _jumbleNode(), save the initial
> jumble_len and the jumble contents when starting, then complain if the
> jumble_len matches with the initial length at the end and if the
> contents are the same in an assert.  A check on the length may be
> enough, but we'd depend on JUMBLE_SIZE and nodes can get pretty big.
>
> What do you think?

If it's for Assert enabled builds only, then to save from having to
look at the buffer, you could have an extra field similar to
jumble_len, but does not get reset when the jumble buffer fills.  Just
assert that the total_jumbled_bytes has grown after jumbling a node,
maybe?

David