| Subject | Re: Reading unnecessary records |
|---|---|
| Author | Dmitry Yemanov |
| Post date | 2014-04-04T17:19:48Z |
04.04.2014 21:07, Leyne, Sean wrote:
correct. There's no difference in this regard between v1.x and v2.x though.
engine perfectly reports record level statistics on a per table basis,
this is a much better proof.
slower than logically the same but streamlined query.
Dmitry
>Firebird does not eliminate unreferenced tables from retrieval, so he's
> But you are assuming that because the PLAN shows that a non-referenced table is actually being read during execution. That may not be the case.
correct. There's no difference in this regard between v1.x and v2.x though.
> The real test to confirm is running the queries and looking at the total of READs and FETCHes.Checking page level statistics is a waste of time in this case. The
engine perfectly reports record level statistics on a per table basis,
this is a much better proof.
> Views are no slower than the same as standalone SQL, this has been tested/benchmarked and confirmed.View is no slower than its replacement as a derived table, but it can be
slower than logically the same but streamlined query.
Dmitry