Slick 3.0 bulk insert or update (upsert)

Question

what is the correct way to do a bulk insertOrUpdate in Slick 3.0?

I am using MySQL where the appropriate query would be

INSERT INTO table (a,b,c) VALUES (1,2,3),(4,5,6)
ON DUPLICATE KEY UPDATE c=VALUES(a)+VALUES(b);

MySQL bulk INSERT or UPDATE

Here is my current code which is very slow :-(

// FIXME -- this is slow but will stop repeats, an insertOrUpdate
// functions for a list would be much better
val rowsInserted = rows.map {
  row => await(run(TableQuery[FooTable].insertOrUpdate(row)))
}.sum

What I am looking for is the equivalent of

def insertOrUpdate(values: Iterable[U]): DriverAction[MultiInsertResult, NoStream, Effect.Write]

Solution 1

There are several ways that you can make this code faster (each one should be faster than the preceding ones, but it gets progressively less idiomatic-slick):

• Run insertOrUpdateAll instead of insertOrUpdate if on slick-pg 0.16.1+

  await(run(TableQuery[FooTable].insertOrUpdateAll rows)).sum
  

• Run your DBIO events all at once, rather than waiting for each one to commit before you run the next:

  val toBeInserted = rows.map { row => TableQuery[FooTable].insertOrUpdate(row) }
  val inOneGo = DBIO.sequence(toBeInserted)
  val dbioFuture = run(inOneGo)
  // Optionally, you can add a `.transactionally`
  // and / or `.withPinnedSession` here to pin all of these upserts
  // to the same transaction / connection
  // which *may* get you a little more speed:
  // val dbioFuture = run(inOneGo.transactionally)
  val rowsInserted = await(dbioFuture).sum
  

• Drop down to the JDBC level and run your upsert all in one go (idea via this answer):

  val SQL = """INSERT INTO table (a,b,c) VALUES (?, ?, ?)
  ON DUPLICATE KEY UPDATE c=VALUES(a)+VALUES(b);"""
  
  SimpleDBIO[List[Int]] { session =>
    val statement = session.connection.prepareStatement(SQL)
    rows.map { row =>
      statement.setInt(1, row.a)
      statement.setInt(2, row.b)
      statement.setInt(3, row.c)
      statement.addBatch()
    }
    statement.executeBatch()
  }
  

Solution 2

As you can see at Slick examples, you can use ++= function to insert using JDBC batch insert feature. Per instance:

val foos = TableQuery[FooTable]
val rows: Seq[Foo] = ...
foos ++= rows // here slick will use batch insert

You can also "size" you batch by "grouping" the rows sequence:

val batchSize = 1000
rows.grouped(batchSize).foreach { group => foos ++= group }