Re: Statistics Import and Export
| От | Corey Huinker |
|---|---|
| Тема | Re: Statistics Import and Export |
| Дата | |
| Msg-id | CADkLM=eu72o_=s2ARNe8yB-16AUm+_iU0tq_ALeeUUxCCqJkOQ@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: Statistics Import and Export (Jeff Davis <pgsql@j-davis.com>) |
| Список | pgsql-hackers |
function attribute_statsitics_update() is significantly shorter. (Thank
you for a good set of tests, by the way, which sped up the refactoring
process.)
yw
* Remind me why the new stats completely replace the new row, rather
than updating only the statistic kinds that are specified?
because:
- complexity
- we would then need a mechanism to then tell it to *delete* a stakind
- we'd have to figure out how to reorder the remaining stakinds, or spend effort finding a matching stakind in the existing row to know to replace it
- "do what analyze does" was an initial goal and as a result many test cases directly compared pg_statistic rows from an original table to an empty clone table to see if the "copy" had fidelity.
- we'd have to figure out how to reorder the remaining stakinds, or spend effort finding a matching stakind in the existing row to know to replace it
- "do what analyze does" was an initial goal and as a result many test cases directly compared pg_statistic rows from an original table to an empty clone table to see if the "copy" had fidelity.
* I'm not sure what the type_is_scalar() function was doing before,
but I just removed it. If it can't find the element type, then it skips
over the kinds that require it.
that may be sufficient,
* I introduced some hard errors. These happen when it can't find the
table, or the attribute, or doesn't have permissions. I don't see any
reason to demote those to a WARNING. Even for the restore case,
analagous errors happen for COPY, etc.
I can accept that reasoning.
* I'm still sorting through some of the type info derivations. I
think we need better explanations about why it's doing exactly the
things it's doing, e.g. for tsvector and multiranges.
I don't have the specifics of each, but any such cases were derived from similar behaviors in the custom typanalyze functions, and the lack of a custom typanalyze function for a given type was taken as evidence that the type was adequately handled by the default rules. I can see that this is an argument for having a second stats-specific custom typanalyze function for datatypes that need them, but I wasn't ready to go that far myself.
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