Re: Heap page diagnostic/test functions (WIP) - Mailing list pgsql-patches

From Tom Lane
Subject Re: Heap page diagnostic/test functions (WIP)
Date
Msg-id 21214.1173123067@sss.pgh.pa.us
Whole thread Raw
In response to Heap page diagnostic/test functions (WIP)  ("Simon Riggs" <simon@2ndquadrant.com>)
Responses Re: Heap page diagnostic/test functions (WIP)  ("Simon Riggs" <simon@2ndquadrant.com>)
Re: Heap page diagnostic/test functions (WIP)  (Gregory Stark <stark@enterprisedb.com>)
List pgsql-patches
"Simon Riggs" <simon@2ndquadrant.com> writes:
> WIP patch for diagnostic/test functions for heap pages. (Linked to
> discussion thread on -hackers "HOT - Whats Next?")

--- no security checks; surely these must be superuser-only.

--- relation_open will succeed on things that don't have storage;
better use heap_open (and check it's not a view).

--- most of the validation functions are quite pointless as bufmgr will
refuse to load a page with bad header data.

> Specifically designed to allow test cases to be written that prove that
> HOT works,

Exactly what will these allow that you can't do with inspection of ctid
etc?  (I suspect your answer will be "can't see infomask", but I'd
rather expose that as a new system column than invent functions like
these.)  I'm pretty dubious of the premise anyway --- to get results
sufficiently constant that the current regression test comparison
mechanism works for them, I think you'll have to constrain the test
conditions so much that the test will prove little or nothing.

            regards, tom lane

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