What is the right way to work with slick's 3.0.0 streaming results and Postgresql?
Solution 1:
The "right way" to do streaming with Slick and Postgres includes three things:
Must use db.stream()
Must disable
autoCommitin JDBC-driver. One way is to make the query run in a transaction by suffixing.transactionally.Must set
fetchSizeto be something else than 0 or else postgres will push the whole resultSet to the client in one go.
Ex:
DB.stream(
find(0L, 0L)
.transactionally
.withStatementParameters(fetchSize = 1000)
).foreach(println)
Useful links:
https://github.com/slick/slick/issues/1038
https://github.com/slick/slick/issues/809