The jdbcloader runtime affects query speed

Question

I have not using jdbcloader that the query time is 140ms, It is very fast. But Run jdbcloader, the query time 480ms, Pls give me a solution.

BTW: this jdbcloader speed is 47000 row/s Tks

Answer 1

Unfortunately, this seems like expected behavior. The Jdbcloader is inserting tens of thousands of records per second, so your query time is going to be negatively effected. It's a lot like the difference between driving on an empty highway versus driving in a traffic jam at rush hour.

The best solution to this would be not to run the Jdbcloader at the same time as your other queries. But if you must do this, you could try using the --batch argument of the Jdbcloader. The default is 200; you could try using a number far lower than that to see if it helps.

Alternatively, you could use the --procedure=TABLE.insert argument (where TABLE is your table name). This sets the Jdbcloader to use single row inserts instead of whole batches, which might allow your other inserts to work better.

Note that --batch and --procedure are mutually exclusive arguments. See this section of the docs for more information:

https://docs.voltdb.com/UsingVoltDB/clijdbcloader.php

It is possible that other Jdbcloader arguments listed there could be useful as well.

Full disclosure: I work at VoltDB.