Data base size estimation for a table having 1 Crore rows:

Data base size estimation for a table for 1 Crore rows:

Columns	Datatypes	Row Size in bytes	Index key size
timestamp	INTEGER	4
l_node	INTEGER	4	4
slot	SMALLINT	2	2
port	SMALLINT	2	2
vpi	SMALLINT	2	2
vci	INTEGER	4	4
subobject	SMALLINT	2	2
stat	SMALLINT	2	2
bucket	SMALLINT	2	2
total	FLOAT	8
peak	FLOAT	8
		40+9 =49	20 + 9 = 29

· Additional 9 bytes for slot entry while write the data to disk

Index size calculation:

Total Index size = 29 bytes

Account for Index Overhead = 36.25 bytes (29*1.25)

Initital table size = 10000000 bytes (1 crore rows)

Total index space needed = 362500000 bytes (36.25* 10000000)

Conversion to KB = 354003.90625 KB (345 MB)

Data size calculation:

Page length in bytes = 2048 – 28 = 2020 bytes **

Row length = 49 bytes

Rows per page = 2020/49 = 41 rows

Noof Datpags for table of 1c row = 243902 Pages (10000000/41) ****

Total pages to store data = 499511296 bytes (476 MB) *******

Approximate total space needed = 476(datasize)+345(index size) = 821 MB

** 28 bytes subtracted for page overhead

**** Total no of rows / rows per page

******* No of Data pages * 2048