Seagate ST43401N/ND Instalační příručka stáhnout pdf (Strana 59)

CHAPTER 5 Implement: Making Required Application Changes

• Inner joins, in which the joined table includes only the rows of the inner

and outer tables that meet the conditions of the on clause. The result set of

a query that includes an inner join does not include any null supplied rows

for the rows of the outer table that do not meet the conditions of the on

clause. The syntax for an ANSI inner join is:

select select_list

from table1 inner join table2

on join_condition

For example:

select au_id, titles.title_id, title, price

from titleauthor inner join titles

and price > 15

• Outer joins, in which the joined table includes all the rows from the outer

table whether or not they meet the conditions of the on clause. If a row

does not meet the conditions of the on clause, values from the inner table

are stored in the joined table as null values. The where clause of an ANSI

outer join restricts the rows that are included in the query result. ANSI

syntax also allows you to write nested outer joins. The syntax for an ANSI

outer join is:

select select_list

from table1 {left | right} [outer] join table2

on predicate [join restriction]

For example:

select au_fname, au_lname, pub_name

from authors left join publishers

on authors.city = publishers.city

For more information see the Transact-SQL User’s Guide at

http://manuals.sybase.com/onlinebooks/group-as/srg1100e/sqlug

dsync Function

Beginning with version 12, Adaptive Server initializes UNIX file system

devices using the

dsync option to ensure recovery. This could cause a

performance impact to servers using file system devices for

tempdb. If you

require earlier behavior or performance characteristics, change the

dsync

setting using

sp_deviceattr.

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Seagate ST43401N/ND Instalační příručka Strana 59