| Subject | Re: [firebird-support] Re: Why does Firebird write so much data for simple select queries? |
|---|---|
| Author | Helen Borrie |
| Post date | 2011-10-28T07:15:30Z |
At 07:36 PM 28/10/2011, ma_golyo wrote:
./hb
>Hi!Firebird will write the intermediate set[s] to disk *if* the RAM available is insufficient. But it does not cause the database file to grow: if these intermediates are written to disk, they are in separate files, not on database pages, and these files are deleted when the transaction is committed or rolled back.
>
>"Firebird doesn't write anything to disk for a Select,..."
>
>That's not true. Firebird writes the resultset on HDD when SELECT contains ORDER BY (maybe PLAN SORT affect that), and does the ordering in this file.
./hb