How does DB2 determine what lock- size to use?

Correct Answer: a nonmatching index scan if ACCESSTYPE = 1

Correct Answer: DeCLarations GENerator : used to create the host language copy books for the table definitions Also creates the DECLARE table

Correct Answer: Cursor is a programming device that allows the SELECT to find a set of rows but return them one at a time Cursor should be used because the host language can deal with only one row at a time

Correct Answer: Both these are used to combine the results of different SELECT statements UNION - Selects only distinct values UNION ALL - Selects duplicate values also Syntax: SELECT column_name(s) FROM table1 UNION / UNION ALL SELECT column_name(s) FROM table2; Notice that each SELECT statement within the UNION must have the same number of columns The columns must also have similar data types Also, the columns in each SELECT statement must be in the same order

Correct Answer: Use SELECT DISTINCT in DB2 query The DISTINCT keyword can be used to return only distinct (different) values Syntax: SELECT DISTINCT column1,column2 FROM table_name;

Correct Answer: A DB2 utility used to collect statistics about the data values in tables which can be used by the optimizer to decide the access path It also collects statistics used for space management These statistics are stored in DB2 catalog tables

Correct Answer: To insert a NULL, move -1 to the null indicator To insert a valid value, move 0 to the null indicator

Correct Answer: REORG reorganizes data on physical storage to reclutser rows, positioning overflowed rows in their proper sequence, to reclaim space, to restore free space It is used after heavy updates, inserts and delete activity and after segments of a segmented tablespace have become fragmented

Correct Answer: SELECT statement has resulted in retrieval of more than one row

Correct Answer: There are three types of lock, namely: Shared ? This type of lock permits two or more programs to read from the locked space but does not allow them to change it Update ? This lock is more lenient It permits the program to read and change the locked space Exclusive ? This lock restricts all users from accessing the locked space