Extremely slow batch insert

I am using this schema:

        let tableCreationSQL =
            $"CREATE TABLE IF NOT EXISTS {tableName} (
                instrument varchar NOT NULL,
                ts timestamp without time zone NOT NULL,
                price decimal NOT NULL,
                volume decimal NOT NULL
            );

            CREATE INDEX IF NOT EXISTS idx_instrument ON {tableName}(instrument);
            CREATE INDEX IF NOT EXISTS idx_ts ON {tableName}(ts);"

and this insertion code:

    let insertTradesAsync (trades: TradeData list) : Async<Result<int, Exception>> =
        async {
            try
                let data =
                    trades
                    |> List.map (fun t ->
                            [
                                "@instrument", Sql.text      t.Instrument.Ticker
                                "@ts",         Sql.timestamp t.Timestamp.DateTime
                                "@price",      Sql.decimal   t.Price
                                "@volume",     Sql.decimal   (t.Quantity * t.Price)
                            ]
                        )

                let! result =
                    connectionString
                    |> Sql.connect
                    |> Sql.executeTransactionAsync [ "INSERT INTO buffer_trades (instrument, ts, price, volume) VALUES (@instrument, @ts, @price, @volume)", data]
                    |> Async.AwaitTask
                return Ok (List.sum result)

            with ex ->
                return Error ex
        }

When inserting batches of 500 to 3000 records, it will take between 20 and 80 seconds. When I do batches of 100, It takes 3-5 seconds to do the insertion.

Is there anything wrong in the way I’m using the lib?

[JesseALancaster]

I confirmed by turning on logging, that this is not batch support,

    "INSERT INTO ... VALUES (@number)", [
            [ "@number", Sql.int 1 ]
            [ "@number", Sql.int 2 ]
            [ "@number", Sql.int 3 ]
        ]

Creates 3 statements as the docs indicate, so while saving on a commit until the end is great and an important feature, it’s not surprising it’s slow if the goal is batch insertion.

@Zaid-Ajaj is there a way to create a SINGLE insert statement with multiple sets of values, so the result is

INSERT INTO ... VALUES 
("@number", Sql.int 1),
("@number", Sql.int 2),
("@number", Sql.int 3)

?

[Zaid-Ajaj]

@thomasd3 @Ildhesten Npgsql.FSharp v5.0.1 has been published, it now uses the batch API thanks to @Ildhesten please give it a go and let me know how it goes 🙏