On Tue, Dec 06, 2011 at 06:36:27PM +0100, Fabian Groffen wrote:
On 06-12-2011 18:24:51 +0100, Stefan Manegold wrote:
To check which MAL statement causes the excessive (intermediate) result creation, you can use the "stethoscope" tool to "listen" to teh server. Before running your query via mclient, start (in a separate terminal) the stethoscope tool as follows:
stethoscope -u <username> -P <password> -D <database_name>
Do not redirect or pipe the output to a files, as this might loose some data due to a yet unresolved bug / design flaw. Rather, once the query finishes (or crashes) cut&paste the stethoscope output from the terminal to a file.
In fact, redirecting the output to a file probably makes the data loss less, since writing to file is often faster than writing to a terminal.
It is unavoidable that data gets lost when there is a large amount of events being generated, and you can't tell other than when you figure parts must be missing.
Well, the most important information we need in this case is the very last MAL statement issued that keeps the server busy (with creating a very large intermediate result); hence, loss of some previous statements is actually really a big problem in this case.
Stefan