Thread: restricting select statements
I'm working with JDBC and if I issue a broad SELECT statement, with a good amount of records (2000) it takes quite a while to execute the query and send the results back, even up to a minute, when I only want about the first 100 records. If I restrict the search, it is satisfied in a much more reasonable amount of time. The problem is that I can only know how big the database. I could do a count and get an idea of how large the database is and make a guess that the data is uniformly distributed. There was a java command to restrict the number of records saved setMaxSize(); but this does not seem to decrease the time of execution of executeQuery(), and probably only uses less local memory. If I have a statement like: SELECT * FROM a; and only want about the first 150 records, is there a way of speeding up the query without doing a count(*) on a and doing something like this: SELECT * FROM a WHERE '' <= a AND a < 'C'; -- Bob VonMoss mailto:bvonmoss@bigfoot.com from Chicago, IL
> I'm working with JDBC and if I issue a broad SELECT statement, with a > good amount of records (2000) it takes quite a while to execute the > query and send the results back, even up to a minute, when I only want > about the first 100 records. If I restrict the search, it is satisfied > in a much more reasonable amount of time. The problem is that I can only > know how big the database. I could do a count and get an idea of how > large the database is and make a guess that the data is uniformly > distributed. There was a java command to restrict the number of records > saved setMaxSize(); but this does not seem to decrease the time of > execution of executeQuery(), and probably only uses less local memory. have a look at using cursors. worked for me. -- [ Jim Mercer Reptilian Research jim@reptiles.org +1 416 410-5633 ] [ The telephone, for those of you who have forgotten, was a commonly used ] [ communications technology in the days before electronic mail. ] [ They're still easy to find in most large cities. -- Nathaniel Borenstein ]