 |
 |
Archives of the TeradataForum
Message Posted: Wed, 28 Feb 2007 @ 10:52:41 GMT
| Subj: | | Re: Problem Returning Time |
| |
| From: | | Victor Sokovin |
| | I have a problem recording the timestamp in a table. For example, I run a "Select timestamp" and returns me the right time at sometimes,
but sometimes not. | |
| | I heard that could be because the nodes have a different time. Could I get the right time without modifying the time in all nodes?? | |
Interesting question! NCR acknowledge the fact that you cannot expect clock synchronization across nodes (MPP feature / vulnerability,
depending on the point of view). One of the consequences is that the queue mechanism in Teradata is not exactly FIFO if you don't take special
care about it.
I don't know how exactly "sel current_timestamp" is routed to a particular node. Perhaps in the same way as any other query is (worth checking,
though). Suppose it is the case. If you need absolute consistency in timestamps and would rather rely on one node's clock you might experiment
with query routing by running those "sel current_timestamp" under a special user all requests of which are forwarded to one (and the same) node.
Perhaps something worth experimenting with?
Regards,
Victor
| |
