Hey, It's configurable by using property queryParallelism and by default, an SQL query is executed in a single thread on each participating Ignite node. Please refer this documentation for additional information:
https://apacheignite-sql.readme.io/docs/performance-and-debugging#section-query-parallelism Evgenii 2018-05-18 2:56 GMT+03:00 Sanjeev <[email protected]>: > Hi, > > I would like to understand how SQL queries are executed on Ignite Server > Nodes. Each Ignite Server Node has some number of primary partitions it is > responsible for. When a query is sent, let' say through JDBC interface, > this > query is routed to all the server nodes where data resides. So the question > is, if a server node has 5 primary partitions it is responsible for, does > the server node spawn multiple threads and process these partitions > concurrently, or does it use a single thread, and process partitions 1 by > 1, > keeping temporary results in memory. > > If it does process partitions concurrently on a single node, another > question is, if there are more number of partitions than available cores, > is > it smart enough to grab all available cores, and then cycle through all > partitions in chunks of available cores keeping temporary results in memory > and merging them as needed. > > I am trying to get a sense of the SQL query processing engine and its > internals especially within a single server node. > > Thanks... > > > > -- > Sent from: http://apache-ignite-users.70518.x6.nabble.com/ >
