Subject Re: [firebird-support] select very slow for no reason / First Skip seam to no work efficiently !
Author Dimitry Sibiryakov
> so why in the previous request, Whith
> Select First 200 skip 0 it's look like that
> the engine scan all the table (5 800 000 indexed read)
> when i want only the First 200 ? like you see
> in the second query if i force que engine
> to return only the first 200 records by a filter
> instead by the first 200 skip 0 it's very
> fast...

First query can't use plan ORDER because your clause "order by"
doesn't include all fields from index. Change it to "order by UserID
desc, randomseed desc".