I made notes to help you, check em out.
Execution plan how to
Run simple Query
Press Crtl – M, Crtl – L
Read left to right
Data is pulled from the database (arrow shows data flow)
Note: Table scan is when query forces storage engine to walk throguh a heap row by row searching everything. This is caused by not using a where clause and an index is not being referenced.
A thicker arrow means more data.
Hover over the arrow to see # of rows
% represents relative cost
0% operators still have a small cost
Operator costs tells accumulated optimizer cost for this step and all previous steps from right to left
Tooltips Example:
To see text:
SET SHOWPLAN_ALL ON;
SET SHOWPLAN_ALL OFF;
In order to turn the text version of the actual execution plan on or off, use the code in
Listings 1.7 and 1.8, respectively.
SET STATISTICS PROFILE ON;
Listing 1.7
SET STATISTICS PROFILE OFF;
