MC Statement 1: When opting for hard drive back-ups to maintain data availability in case of a calamity, the RPO depends on the underlying infrastructure. Choosing a SAN as storage subsystem might be a solution here, as it keeps the burden of data and backup related traffic from the LAN and from the servers.
Statement 2: Log shipping is a technique which is used for preserving the transaction context of a DBMS in case of a calamity. The remote DBMS used for replication can use the primary log for restoring transactions that were ongoing at the primary site.
Which statements are correct or wrong? Statement 1 is correct, statement 2 is wrong. incorrect Statement 1 is wrong, statement 2 is correct. correct Both statements are wrong. incorrect Both statements are correct. incorrect
MC Which statement is CORRECT? Current versions of SQL require a specific internal data model. incorrect Current versions of SQL impose a specific physical implementation of internal data models. incorrect Current versions of SQL do not impose any standardization on the internal data model nor on the way in which a relational data model is implemented physically. correct Current versions of SQL require both a specific internal data model AND a specific physical implementation of that data model. incorrect
MC Which statement is CORRECT? Table cardinality is another way of referring to the number of columns in a table. incorrect SQL is a declarative language, meaning that the programmer has to specify what data to retrieve and how the data is to be located and retrieved from the physical database files. incorrect If no further statistical information about a predicate is available, the filter factor of that predicate can be estimated by dividing 1 by the number of different values the attribute type can have. correct The filter factor of a predicate is the fraction of rows that contain a missing value for that predicate. incorrect
MC Which statement is NOT CORRECT? An index can be used to create a physical ordering of rows. incorrect Indexing makes it harder to enforce uniqueness on a (combination of) column(s). correct An index implies a logical ordering of the rows in a table. incorrect Index creation can help improve the performance of join queries. incorrect
MC Which statement is CORRECT? Current versions of SQL impose a specific physical implementation of internal data models. incorrect Current versions of SQL do not impose any standardization on the internal data model nor on the way in which a relational data model is implemented physically. correct Current versions of SQL require a specific internal data model. incorrect Current versions of SQL require both a specific internal data model AND a specific physical implementation of that data model. incorrect
MC Which statement is NOT CORRECT? Block level striping as used in RAID 0 does not increase read performance. correct To store the same amount of data, RAID 1 needs twice the amount of storage capacity compared to RAID 0. incorrect RAID level 5 strikes a balance between read and write performance, storage efficiency, and fault tolerance. incorrect RAID level 0 is used if performance is more important than fault tolerance. incorrect
MC Given 2 tables R and S. Which of the following join strategies is described by the following algorithm:
Stage 1:
sort R according to r(a)
sort S according to s(b)
Stage 2:
retrieve the first row r of R
retrieve the first row s of S
for every row r in R do {
while s(b) < r(a) do {
read the newt row s of S
if r(a) = s(b) then join r with s and place in output buffer
}
} Hash join incorrect Sort-Merge join correct Nested loop join incorrect None of these join strategies incorrect
MC Which statement is NOT CORRECT? Although SCSI has been a popular medium for connecting storage devices to servers and/or processors in the past, nowadays, it is not used anymore for high performance and high capacity workstations and servers. correct The management of data storage is more expensive than the purchase of storage hardware, which is why businesses opt for enterprise storage subsystems. incorrect The SCSI I/O command set is a type of block-level I/O protocol which can be exchanged over SCSI, Ethernet or Fibre Channel cabling. incorrect 'Network attach' refers to establishing a many-to-many connection between storage devices and the corresponding servers by means of network technology. incorrect
MC Given 2 tables R and S. Which of the following join strategies is described by the following algorithm:
Stage 1:
sort R according to r(a)
sort S according to s(b)
Stage 2:
retrieve the first row r of R
retrieve the first row s of S
for every row r in R do {
while s(b) < r(a) do {
read the newt row s of S
if r(a) = s(b) then join r with s and place in output buffer
}
} Nested loop join incorrect Sort-Merge join correct None of these join strategies incorrect Hash join incorrect
MC Statement 1: When opting for hard drive back-ups to maintain data availability in case of a calamity, the RPO depends on the underlying infrastructure. Choosing a SAN as storage subsystem might be a solution here, as it keeps the burden of data and backup related traffic from the LAN and from the servers.
Statement 2: Log shipping is a technique which is used for preserving the transaction context of a DBMS in case of a calamity. The remote DBMS used for replication can use the primary log for restoring transactions that were ongoing at the primary site.
Which statements are correct or wrong? Statement 1 is correct, statement 2 is wrong. incorrect Both statements are wrong. incorrect Statement 1 is wrong, statement 2 is correct. correct Both statements are correct. incorrect