Other well known dbms's do have this possibility, because they place deleted or updated records in a separate table or file (plz correct me if i'm wrong). But this has other, greater performance disadvantages. The count(*) problem is a bit of a publicity problem rather than a real performance problem (i've been told). People are aware of the fact that count(*) is faster in other dbms's, but "we" don't want superficial things like optimizing count(*) for publicity ruin other, more important things for us, performance-wise.
On Sat, Mar 5, 2011 at 11:46 PM, John R Pierce
<pierce@hogranch.com> wrote:
On 03/05/11 2:05 PM, Allan Kamau wrote:
Is it possible in theory to efficiently perform count the primary or
unique indices underlying data structures, regardless whether there is
a WHERE clause detailing filtration base on values from such index or
not?
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