Mickael, Not knowing your query, it sounds like your method is working correctly. It is quite normal to have the initial query take longer than subsequent queries. This is a cache effect and is what databases, in general, strive for performance-wise. I suspect that the second time you run the query that it does not take 0ms, just less than 1ms.
Ken On Sat, Jul 21, 2007 at 03:26:19PM +0200, Mickael DELOISON wrote: > Hello, > > I am trying to get the execution time of a query by using JDBC (Java). > To do that I make the difference between the time (in milliseconds) > after the query execution and the time before the query execution. > > The first time I do that, I get the real execution time, but the query > plan seems to be cached. And the next time I do the same operation, > for a simple query I do not get the real time (in fact my 'simple' > query seems to execute in 0 millisecond). > > So I need help: I would like to solve this problem but I do not know > how. I have tried some researches on Internet but I did not find. Is > there a possibility to disable the query plan cache temporarily? It is > also possible I am totally wrong and the problem is not where I see > it... Anyway I need help. > > Thank you in advance, > Mickael > > ---------------------------(end of broadcast)--------------------------- > TIP 9: In versions below 8.0, the planner will ignore your desire to > choose an index scan if your joining column's datatypes do not > match > ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
