Обсуждение: Print b-tree tuples
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
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
Вложения
Hello,
I was able to get around this by only printing byval attributes: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;
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
Samuel Vogel <s@muel-vogel.de> 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
Am 04.01.13 21:26, schrieb Tom Lane: > Samuel Vogel <s@muel-vogel.de> 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