If we have a query of the form:
Select *, (Select * FROM T2 WHERE p2 = T1.p1) FROM T1 ORDER
BY 1 WHERE p3 = 75
In SQL, if a subselect is present in the column-list, is the
result set of this subselect considered to be a part of a
single tuple returned from the outer query, or does the result
set
If we have a query of the form:
Select *, (Select * FROM T2 WHERE p2 = T1.p1) FROM T1 ORDER BY 1 WHERE p3 = 75
In the above query there is a subselect in the target list and the ORDERBY has
an ordinal number which indicates order by column 1. Does this mean that the
above query will return all
r
> To: "amit sehas"
> Cc: pgsql-hackers@postgresql.org
> Date: Wednesday, December 21, 2011, 8:43 AM
> On Thu, Dec 15, 2011 at 4:15 PM, amit
> sehas
> wrote:
> > I had a question about the cursor internals
> implementation. When you Fetch next 'n'
If a field(attribute) in a type is declared to be an array. Then is it always
the case that the array will be packed into a single tuple that resides in the
database. There is the TOAST mechanism for oversized tuples but that is still
considered to be a single tuple. Is there any circumstance in
HI,
I had a question about the cursor internals implementation. When you Fetch next
'n' results without moving the cursors, is this kind of functionality
implemented by firstly executing the whole query and then moving the cursor
over the results, or are the movements done on active database lo
We are making some performance measurements, we are trying to determine query
execution behavior. Lets say we have 4 tables T1, T2, T3 and T4
and the query has the form:
select * from T1, T2, T3, T4 where (T1.a = T2.b and T2.c = T3.d
T3.e = T4.f)
where a,b,c,d,e,f are properties of the re
HI,
for the histograms for cost based optimization, is there a rule of thumb on how
often to rebuild them? They are obviously not being continuously updated...what
is the state of the art in this area, do all the other databases also end up
with stale statistics every now and then and have to k
