fastest way to read and iterate over the rows of a table, and read/call a function with corresponding arguments and raw data from each row?

I have 2 tables with me.

1st table is tab having funtion_name and args column like below

tab:flip `function`root`args!(`symbol$();();());
insert[`tab](`.qa.test1;"ES";`startDate`endDate`roots`rollPerct`expDateThreshold`expDateThresholdExpiry!(2010.01.01d;2010.12.31;`ES;0.8;10;1));
insert[`tab](`.qa.test1;"NQ;SI";`startDate`endDate`roots`rollPerct`expDateThreshold`expDateThresholdExpiry!(2010.01.01d;2013.12.31;`NQ`SI;0.8;20;1));
insert[`tab](`.qa.test1;"ALL";`startDate`endDate`roots`rollPerct`expDateThreshold`expDateThresholdExpiry!(2010.01.01d;2013.12.31;`HQ`ZK`NA`PL`BZ;0.8;12;2));

2nd table is raw having raw data like below

//create sample data
raw:([]date:`date$();sym:`symbol$();name:`symbol$();expiration_date:`date$());
//modify data to simulate requirement 
{`raw insert (x;`ESH10;`someName1;2010.01.10)} each (2010.01.01 + til 31);
{`raw insert (x;`ESH11;`someName2;2010.01.15)} each (2010.01.01 + til 31);
{`raw insert (x;`ESH12;`someName3;2010.01.20)} each (2010.01.01 + til 31);
{`raw insert (x;`ESH13;`someName4;2010.01.16)} each (2010.01.01 + til 31);
{`raw insert (x;`ESH14;`someName5;2010.01.13)} each (2010.01.01 + til 31);
{`raw insert (x;`ESH15;`someName6;2010.01.28)} each (2010.01.01 + til 31);

Now I want Iterate each row of table tab to call the function written in the function column along with the args + raw table as input
some like

.qa.test1[(`startDate`endDate`roots`rollPerct`expDateThreshold`expDateThresholdExpiry!(2010.01.01d;2010.12.31d;`ES;0.8;10;1));raw]
.qa.test1[(`startDate`endDate`roots`rollPerct`expDateThreshold`expDateThresholdExpiry!(2010.01.01d;2013.12.31d;`NQ`SI;0.8;20;1));raw]
.qa.test1[(`startDate`endDate`roots`rollPerct`expDateThreshold`expDateThresholdExpiry!(2010.01.01d;2013.12.31d;`HQ`ZK`NA`PL`BZ;0.8;12;2));raw]

The solution I came up with is below, its working but its very slow.

Is there a Better Way of doing this in kdb+?

Note: The data I am dealing with is huge having 8000000 rows.

//solution which is slow
.qa.get_tab_main:{[raw]
//raw is the table having raw data, .qa.test1 accepts 2 args .qa.test1[args;raw] 
    //iterate over the table rows and append the result to tab table
    cnt:(count tab);
    ino:0;
    res1::flip `date`sym`name`expiration_date!(`date$();`symbol$();`symbol$();`date$()); //meta of final output table from .qa.test1
    while[ino<cnt;
     data:exec .[first function;(args;raw)] from tab where i=ino;
     upsert[`tab;(select from data)];
     ino:ino+1
     ];
    res:`date xasc res1;
    delete res1 from `.;
    res
    };

Using qsql:

q)exec value each(function,'(enlist each args),\:enlist raw) from tab

You can raze the result if you want a single table output.