Re: Declarative partitioning

>
> Sorry for replying so late.
>

No worries! We have jobs to do aside from this.

>
> Everything seemed to go dandy until I tried FOR VALUES (blah , blah],
> where psql wouldn't send the command string without accepting the closing
> parenthesis, :(. So maybe I should try to put the whole thing in '', that
> is, accept the full range_spec in a string, but then we are back to
> requiring full-blown range parse function which I was trying to avoid by
> using the aforementioned grammar. So, I decided to move ahead with the
> following grammar for time being:
>
> START (lower-bound) [ EXCLUSIVE ]
> | END (upper-bound) [ INCLUSIVE ]
> | START (lower-bound) [ EXCLUSIVE ] END (upper-bound) [ INCLUSIVE ]
>
> Where,
>
> *-bound: a_expr
> | *-bound ',' a_expr
>
> Note that in the absence of explicit specification, lower-bound is
> inclusive and upper-bound is exclusive.
>

Thanks for trying. I agree that it would be a full blown range parser, and
I'm not yet advanced enough to help you with that.

So presently partitions that are unbounded on the lower end aren't
possible, but that's a creation syntax issue, not an infrastructure issue.
Correct?

> Okay, perhaps I should not presume a certain usage. However, as you know,
> the usage like yours requires some mechanism of data redistribution (also
> not without some syntax), which I am not targeting with the initial patch.
>

I'm quite fine with limitations in this initial patch, especially if they
don't limit what's possible in the future.

> > Question: I haven't dove into the code, but I was curious about your
> tuple
> > routing algorithm. Is there any way for the algorithm to begin it's scan
> of
> > candidate partitions based on the destination of the last row inserted
> this
> > statement? I ask because most use cases (that I am aware of) have data
> that
> > would naturally cluster in the same partition.
>
> No. Actually the tuple-routing function starts afresh for each row. For
> range partitions, it's binary search over an array of upper bounds. There
> is no row-to-row state caching in the partition module itself.
>
>
bsearch should be fine, that's what I've used in my own custom partitioning
schemes.

Was there a new patch, and if so, is it the one you want me to kick the
tires on?