Re: Print b-tree tuples

Поиск
Список
Период
Сортировка
Искать

Re: Print b-tree tuples

От:
Tom Lane <tgl@sss.pgh.pa.us>
Дата:
Samuel Vogel  writes:
> I'm trying to print out the tuples in the b-tree nodes for analysis, but 
> when iterate over more than the first entry of the tuples (scanKey++), I 
> strangely get the error below on query execution:
> ERROR:  relation "simpletest" does not exist
> LINE 1: SELECT * FROM simpletest WHERE id = 50;

Is this patch the only thing you changed?  The only obvious explanation
for the above error (other than "you fat-fingered the query") seems to
be that you caused index searches in pg_class to fail, but I don't see
how this patch could be affecting the result of _bt_binsrch.
		regards, tom lane

Print b-tree tuples

От:
Samuel Vogel <s@muel-vogel.de>
Дата:
Hello,

I'm trying to print out the tuples in the b-tree nodes for analysis, but when iterate over more than the first entry of the tuples (scanKey++), I strangely get the error below on query execution:
ERROR:  relation "simpletest" does not exist
LINE 1: SELECT * FROM simpletest WHERE id = 50;

Any help with reviewing my my small attached patch would be greatly appreciated!

Regards,
Samuel Vogel

Re: Print b-tree tuples

От:
Samuel Vogel <s@muel-vogel.de>
Дата:
Hello,

I'm trying to print out the tuples in the b-tree nodes for analysis, but when iterate over more than the first entry of the tuples (scanKey++), I strangely get the error below on query execution:
ERROR:  relation "simpletest" does not exist
LINE 1: SELECT * FROM simpletest WHERE id = 50;
I was able to get around this by only printing byval attributes:

if (!itupdesc->attrs[i-1]->attbyval)
            break;

I would still like to know why my code screws up though. The relnames are not byval, but I should still be able to print the address, right?

Regards,
Samuel

Re: Print b-tree tuples

От:
Samuel Vogel <s@muel-vogel.de>
Дата:
Am 04.01.13 21:26, schrieb Tom Lane:
> Samuel Vogel  writes:
>> I'm trying to print out the tuples in the b-tree nodes for analysis, but
>> when iterate over more than the first entry of the tuples (scanKey++), I
>> strangely get the error below on query execution:
>> ERROR:  relation "simpletest" does not exist
>> LINE 1: SELECT * FROM simpletest WHERE id = 50;
> Is this patch the only thing you changed?  The only obvious explanation
> for the above error (other than "you fat-fingered the query") seems to
> be that you caused index searches in pg_class to fail, but I don't see
> how this patch could be affecting the result of _bt_binsrch.
Yes, I've switched to a clean master and only applied this patch. If I 
put the the break, the query works, so it's fine as well.

BTW: I just had a discussion if it would make sense, to recreate my test 
table with a different order, as a b-tree is always dependent on 
insertion order. But as the b-tree index is newly created in memory 
after each restart, two different insertion orders (same values) would 
give me the same b-tree at least after a restart, right?

Regards,
Samuel
FAQ