Archives of the TeradataForum
Message Posted: Mon, 21 Apr 2003 @ 16:56:02 GMT
| Subj: || || Re: Select * from mytable |
| From: || || Dieter Nöth |
Anomy Anom wrote:
| ||MyTable has tens of millions of rows.|| |
| ||The astute user wants to look at the first 2000 rows so they enter:|| |
There are no _first_ rows in a relational table (without Order By).
| ||lock MyTable for access|
Select * from MyTable;
| ||Explain says the query will use an all amps retrieve. Why do the nodes take over 2 minutes to start returning rows when there is no
one on the system? Based on experience with other database systems I expect the system to start returning rows.|| |
Teradata first spools _all_ rows and then starts returning data.
Why don't you use a
Select * from MyTable sample 2000;
This will return 2000 random rows.