Work on q2'

1 files changed, 11 insertions, 0 deletions

diff --git a/doc/unit-7.md b/doc/unit-7.md
index cf471a0..e9edc2f 100644
--- a/doc/unit-7.md
+++ b/doc/unit-7.md
@@ -250,6 +250,17 @@ A common grain would be each business transaction, such as an individual line it
 
 Clicks on a website is possibly the lowest level of granularity.
 
+Size of the fact table
+
+The grain and duration of the fact table have a direct impact on the size of that table.
+
+We can estimate the number of rows in the fact table as follows:
+
+1. Estimate the number of possible values for each dimension associated with the fact table.
+2. Multiple the values obtained in the first step after making any necessary adjustments
+
+Total rows = 1000 stores * (10,000 products * 50% = 5,000) * 24 months
+ = 120,000,000 rows
 
 Multiple fact tables