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96) If I have a view which is a join of two or more tables, can this view be
updateable? –
No.
97) What are the 4 environments which can access DB2 ?
TSO, CICS, IMS and BATCH
98) What is an inner join, and an outer join ?
Inner Join: combine information from two or more tables by comparing all
values that meet the search criteria in the designated column or columns of on e
table with all the clause in corresponding columns of the other table or tables.
This kind of join which involve a match in both columns are called inner
joins.
Outer join is one in which you want both matching and non matching rows to be
returned. DB2 has no specific operator for outer joins, it can be simulated by
combining a join and a correlated sub query with a UNION.
99) What is FREEPAGE and PCTFREE in TABLESPACE creation?
PCTFREE: percentage of each page to be left free
FREEPAGE: Number of pages to be loaded with data between each free
page
100) What are simple, segmented and partitioned table spaces ?
Simple Tablespace:
Can contain one or more tables
Rows from multiple tables can be interleaved on a page under the DBAs control
and maintenance
Segmented Tablespace:
Can contain one or more tables
Tablespace is divided into segments of 4 to 64 pages in increments of 4
pages. Each segment is dedicated to single table. A table can occupy multiple
segments
Partitioned Tablespace:
Can contain one table
Tablespace is divided into parts and each part is put in a separate VSAM
dataset.
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