In TIBCO Data Virtualization, executing the below packaged query against a database runs without any noticeable lag:

SELECT o1.owner, oa1.owner_acc, COALESCE(SUM(CASE WHEN nd1.credit=1 THEN nd1.nom_value ELSE nd1.nom_value*-1 END), 0.00) AS expenditure_prev_year
FROM SQL92.owner_SQL92 AS o1
INNER JOIN SQL92.owner_acc_SQL92 AS oa1 ON oa1.owner=o1.owner AND oa1.owner_acc BETWEEN 2000 and 2999
INNER JOIN SQL92.nomdet_SQL92 AS nd1 ON nd1.owner=o1.owner AND nd1.owner_acc=oa1.owner_acc
AND nd1.acc_year={1}-1 
INNER JOIN SQL92.expense_type_SQL92 AS et1 ON et1.expense_type=nd1.nom_code AND et1.expense_cat BETWEEN 16 and 28
WHERE o1.owner='{0}' 
GROUP BY o1.owner, oa1.owner_acc

After placing the query in a VIEW which contains INNER JOINs (as given below) results in a lag during the query execution.

SELECT {DECLARE inClientNo VARCHAR(10)} owner, {DECLARE inAccYear INTEGER} AccYear, oa1.owner_acc, COALESCE(SUM(CASE WHEN nd1.credit=1 THEN nd1.nom_value ELSE nd1.nom_value*-1 END), 0.00) AS expenditure_prev_year
FROM /shared/Physical/Formatting/Propman/Owner_SQL92 AS o1
INNER JOIN /shared/Physical/Formatting/Propman/Owner_Acc_SQL92 AS oa1 ON oa1.owner=o1.owner AND oa1.owner_acc BETWEEN 2000 and 2999
INNER JOIN /shared/Physical/Formatting/Propman/Nomdet_SQL92 AS nd1 ON nd1.owner=o1.owner AND nd1.owner_acc=oa1.owner_acc 
AND nd1.acc_year=inAccYear-1 
INNER JOIN /shared/Physical/Formatting/Propman/Expense_Type_SQL92 AS et1 ON et1.expense_type=nd1.nom_code AND et1.expense_cat BETWEEN 16 and 28
WHERE o1.owner=inClientNo 
GROUP BY o1.owner, oa1.owner_acc

Note that the above queries are very similar. However, the resulting query sent to the data-source is automatically rewritten by TDV with subqueries after the INNER JOINs. This will add an overhead to the overall query execution time.

SELECT 
    oa1.Owner_Acc AS owner_acc,
    COALESCE(SUM(CASE 
        WHEN nd1.Credit = 1 THEN nd1.Nom_Value
        ELSE (nd1.Nom_Value * (- (1)))
    END), 0.00) AS expenditure_prev_year
FROM (((SELECT 
        Owner_SQL92.Owner
    FROM "SQL92"."Owner_SQL92" Owner_SQL92
    WHERE Owner_SQL92.Owner = '0682') o1 INNER JOIN 
        (SELECT 
            Owner_Acc_SQL92.Owner_Acc,
            Owner_Acc_SQL92.Owner
        FROM "SQL92"."Owner_Acc_SQL92" Owner_Acc_SQL92
        WHERE ('0682' = Owner_Acc_SQL92.Owner )) oa1
    ON o1.Owner = oa1.Owner) INNER JOIN 
        (SELECT 
            Nomdet_SQL92.Credit,
            Nomdet_SQL92.Nom_Value,
            Nomdet_SQL92.Nom_Code,
            Nomdet_SQL92.Owner,
            Nomdet_SQL92.Owner_Acc
        FROM "SQL92"."Nomdet_SQL92" Nomdet_SQL92
        WHERE ('0682' = Nomdet_SQL92.Owner AND Nomdet_SQL92.Acc_Year = (2018 - 1) AND Nomdet_SQL92.Owner_Acc <= 2999 AND Nomdet_SQL92.Owner_Acc >= 2000 )) nd1
    ON o1.Owner = nd1.Owner AND oa1.Owner_Acc = nd1.Owner_Acc) INNER JOIN 
        (SELECT 
            Expense_Type_SQL92.Expense_Type
        FROM "SQL92"."Expense_Type_SQL92" Expense_Type_SQL92
        WHERE Expense_Type_SQL92.Expense_Cat <= 28 AND Expense_Type_SQL92.Expense_Cat >= 16) et1
    ON nd1.Nom_Code = et1.Expense_Type
GROUP BY o1.Owner,
    oa1.Owner_Acc

Append {OPTION DISABLE_SELECTION_REWRITER} parameter in the query to help prevent the QE from re-writing INNER JOINS with SELECT's which results in treating the query as it is written. 

Here is an example query:

SELECT  {OPTION DISABLE_SELECTION_REWRITER}  oa1.Owner_Acc AS owner_acc,     COALESCE(SUM(CASE ....
....
GROUP BY o1.Owner,     oa1.Owner_Acc