Alberto Simões <[EMAIL PROTECTED]>
wrote:
I have a big table (16 million records) and I want to perform JUST
ONCE an operation to sort by one column:
SELECT * FROM tbl ORDER BY i DESC;
Now, is it faster to perform just the select, or to do:
CREATE INDEX tmp ON tbl (i);
SELECT * FROM tbl ORDER BY i DESC;
My understanding is that SQLite implements ORDER BY by effectively
building a temporary index and then iterating over it (unless a suitable
existing index is available, of course). So both approaches should take
approximately the same time.
Why don't you test both (perhaps on a small subset of a real database)
and find out for sure?
Igor Tandetnik
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