Question

 UPDATE
        BondPrices
    SET
        MarketValueOwned = Holdings.Amount
    FROM
        BondPrices BondPrices
        INNER JOIN
        (
            SELECT
                PM.SecurityId,
                SUM(Pos.QuantityTraded * Pos.Mark) AS Amount
            FROM
                Position Pos --WITH (NOLOCK, READUNCOMMITTED)
                INNER JOIN
                PositionMaster PM --WITH (NOLOCK, READUNCOMMITTED)
                       ON
                    Pos.PositionMasterId = PM.PositionMasterId
            WHERE
                Pos.Date = @ReportDate 
            GROUP BY
                PM.SecurityId
        ) Holdings ON
            BondPrices.SecurityId = Holdings.SecurityId
    WHERE
        BondPrices.Date = @ReportDate  

please help me is that correct that i put WITH (NOLOCK, READUNCOMMITTED) inside select statement of update block?
i need to do this for reporting purpose but i’m confused whether it is correct or not?

Answer 1

According to Table Hints (Transact-SQL):

READUNCOMMITTED and NOLOCK cannot be specified for tables modified by insert, update, or delete operations. The SQL Server query optimizer ignores the READUNCOMMITTED and NOLOCK hints in the FROM clause that apply to the target table of an UPDATE or DELETE statement.

Tables Fireball..Position and Fireball_Reporting..PositionMaster aren’t modified so this hint should be fine.

Edit:

I assume that you wanted write READUNCOMMITTED instead of UNCOMMITTED.