Re: TOASTing smaller things

Is this a TODO?

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Jan Wieck wrote:
> On 3/21/2007 2:05 PM, Tom Lane wrote:
> > Chris Browne <cbbrowne(at)acm(dot)org> writes:
> >> #define TOAST_DENOMINATOR 17
> >> /* Use this as the divisor; current default behaviour falls from TOAST_DENOMINATOR = 4 */
> >
> >> #define TOAST_TUPLE_THRESHOLD^I\
> >> ^IMAXALIGN_DOWN((BLCKSZ - \
> >> ^I^I^I^I MAXALIGN(sizeof(PageHeaderData) + 3 * sizeof(ItemIdData))) \
> >> ^I^I^I^I / TOAST_DENOMINATOR)
> >
> > Given that you are quoting code that was demonstrably broken since the
> > original coding of TOAST up till a month or two back, "it passes
> > regression" is not adequate proof of "it's right". In fact I think
> > it's not right; you have not got the roundoff condition straight.
> >
> >> 4. A different mechanism would be to add a fifth storage column
> >> strategy (the present four are PLAIN, EXTENDED, EXTERNAL, MAIN), let's
> >> say, TOAST.
>
> FORCE_COMPRESSION, FORCE_EXTERNAL and FORCE_EXTERNAL_UNCOMPRESSED.
>
> >
> > Anything along this line would require invoking the toaster on every
> > single tuple, since we'd always have to crawl through all the columns
> > to see if toasting was supposed to happen. No thanks.
>
> Not necessarily. A flag in Relation telling if the table has any column
> marked like that could be set while constructing the relcache entry.
>
> >
> >> Which of these sounds preferable?
> >
> > It's a bit late in the cycle to be proposing any of these for 8.3.
>
> Certainly.
>
>
> Jan
>
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