Sample size in ANALYZE command
Posted on 2001-06-29
Is there a recommended rule of thumb for choosing what
percentage of a table to analyse ?
I have some large tables (20 million rows) which I want
to analyse on a regular basis.
I don't want to analyse too small a number of rows, as
the stat's probably won't be accurate, and could make
things worse if the wrong execution path is chosen as
a result of inaccurate stat's.
But I don't want to analyse the whole table as this will
take too long.
What percentage will give me a good balance ? 10 ? 20 ?
Does Oracle recommend a suitable figure ?
Any accompanying explanations or URL's would be most