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 Related Questions Group by controls the presentation of the rows, order by controls the presentation of the columns for the results of the SELECT statement. Latest Answer : Group By forms Groups (of course), but this means it also SORTS; but it will also retrieve a DISTINCT RECORD SETORDER BY Sorts by the columns included in the Statement, and does not retrieve DISTINCT Records.Neither determines the order of the columns ... An embedded sql statement may return a number of rows while the programming language can only access one row at a time. The programming device called a cursor controls the position of the row. Latest Answer : Cursor is a Context Area. where which can process multiples rows. ... Denormalizing DB2 tables reduces the need for processing intensive relational joins and reduces the number of foreign keys. Latest Answer : In datawarehouse environment, mostly all the tables are semi- normalized ( ie it is fully normalized) to reduce no of joins . so de-normalization is having lot of advantages in datawarehouse . ... The two parameters used in the CREATE statement are the PCTFREE which specifies the percentage of free space for each page and FREEPAGE which indicates the number of pages to be loaded with data between A NULL value takes up one byte of storage and indicates that a value is not present as opposed to a space or zero value. It's the DB2 equivalent of TBD on an organizational chart and often correctly Latest Answer : A NULL value is different from a blank or a zeroA NULL value can be inserted into columns of any data typeA NULL value will evaluate to NULL in any expression (e.g.NULL multiplied by 10 is NULL)If a column has a NULL value, Oracle ignores any UNIQUE, ... The number of distinct values for a column is called index cardinality. DB2's RUNSTATS utility analyzes column value redundancy to determine whether to use a tablespace or index scan to search for The three data types are DATE, TIME and TIMESTAMP. CHAR can be used to specify the format of each type. The DAYS function calculates the number of days between two dates. (It's Y2K compliant). Latest Answer : DATE PIC X(10)TIME PIC X(8)TIMESTAMP PIC X(26) ... SQL statements may return any number of rows, but most host languages deal with one row at a time by declaring a cursor that presents each row at a unique isolation level. DB2 can implement a join in three ways using a merge join, a nested join or a hybrid join. Explain the differences. A merge join requires that the tables being joined be in a sequence; the rows are retrieved with a high cluster ratio index or are sorted by DB2. A nested join does not require a sequence and works best on joining a small number of rows. DB2 reads the outer table values and each time scans the inner table for matches. The hybrid join is a nested join that requires the outer table Latest Answer : To answer the original question, for many releases only one column could appear in the result table of a subquery. As of Version 7 of DB2 the result of a subquery is equivalent to a fullselect which means that 750 columns can appear. ... Read Answers (4) | Asked by : jnana
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