Subject | Re: [firebird-support] select very slow for no reason / First Skip seam to no work efficiently ! |
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Author | Dimitry Sibiryakov |
Post date | 2009-12-05T10:49:36Z |
> so why in the previous request, WhithFirst query can't use plan ORDER because your clause "order by"
> 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...
doesn't include all fields from index. Change it to "order by UserID
desc, randomseed desc".
SY, SD.