A file has r = 20, 000 STUDENT records of fixed length. Each record has the following fields: NAME (30 bytes), SSN (9 bytes), ADRESS(40 bytes), PHONE(9 bytes), BIRTHDATE (8 bytes), SEX(1 byte), CLASSCODE( 4 bytes, integer) MAJORDEPTCODE(4 bytes), MINORDEPTCODE(4 bytes), and DEGREEPROGRAM( 3 bytes). An additional byte is used as a deletion marker. Block size B = 512 bytes. a) Calculate the blocking factor bfr (=floor(B/R), where R is the record size) and number of file blocks b, assuming unspanned organization (a record can’t be split across blocks). b) Suppose only 80% of the STUDENT records have a value for PHONE, 85% for MAJORDEPTCODE, 15% for MINORDEPTCODE, and 90% for DEGREEPROGRAM. We use a variable-length record file. Each record has a 1-byte field type for each field in the record, plus the 1-byte deletion marker and a 1-byte end-of-record marker. Suppose that we use a spanned record organization, where each block has a 5-byte pointer to the next block (this space is not used for record storage). Calculate average record size and the number of blocks needed for the file.
A file has r = 20, 000 STUDENT records of fixed length. Each record has the following fields: NAME (30 bytes), SSN (9 bytes), ADRESS(40 bytes), PHONE(9 bytes), BIRTHDATE (8 bytes), SEX(1 byte), CLASSCODE( 4 bytes, integer) MAJORDEPTCODE(4 bytes), MINORDEPTCODE(4 bytes), and DEGREEPROGRAM( 3 bytes). An additional byte is used as a deletion marker. Block size B = 512 bytes.
a) Calculate the blocking factor bfr (=floor(B/R), where R is the record size) and number of file blocks b, assuming unspanned organization (a record can’t be split across blocks).
b) Suppose only 80% of the STUDENT records have a value for PHONE, 85% for MAJORDEPTCODE, 15% for MINORDEPTCODE, and 90% for DEGREEPROGRAM. We use a variable-length record file. Each record has a 1-byte field type for each field in the record, plus the 1-byte deletion marker and a 1-byte end-of-record marker. Suppose that we use a spanned record organization, where each block has a 5-byte pointer to the next block (this space is not used for record storage). Calculate average record size and the number of blocks needed for the file.
GIVEN
A file has r = 20, 000 STUDENT records of fixed length. Each record has the following fields: NAME (30 bytes), SSN (9 bytes), ADRESS(40 bytes), PHONE(9 bytes), BIRTHDATE (8 bytes), SEX(1 byte), CLASSCODE( 4 bytes, integer) MAJORDEPTCODE(4 bytes), MINORDEPTCODE(4 bytes), and DEGREEPROGRAM( 3 bytes). An additional byte is used as a deletion marker. Block size B = 512 bytes.
Trending now
This is a popular solution!
Step by step
Solved in 3 steps
