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Oracle? Oracle, SQL Server? , .
g grid. Grid .
, Grid - , , , , , . Grid computing (, , ) , "" , grid .
, grid-, - Global Grid Forum (GGF) (http://www.gridforum.org). , Oracle, HP, IBM, Intel, Microsoft.
. () , (mainframe), . (Cluster () , , . , , , . , , .. .
. , insert, update, delete select , . , , Oracle . , instead of.
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Oracle , SQL-, .
create view:
create [ or replace ] [ force ] view < > [ (< > {,< >}) ] as < > [ with ( read only | check option [ constraint < >]) ]
( , , ), . force, , :
ORA-04063: view " < > " has errors
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, SQL-. , . , .
with read only , . with check option Oracle insert update . instead of, .
drop:
drop view < >
, . , , . , , . . .
; 16 . . , , ( null), .
Oracle , . . , . , . . , . Oracle unique primary key.
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create index, :
create [ unique | bitmap ] index < > on < > (< > {, < >})
unique .
bitmap , . , B-1. bitmap- , null. bitmap- , , . , bitmap- , . -, . , , . -, bitmap- .
, . drop index: drop index < >
, . .
create sequence:
create sequence < > [ start with < >] [ increment by < >] [ maxvalue < >] [ minvalue < >] [ cycle | nocycle ] [ cache < > | nocache ] [ order | noorder ]
start with increment by , . , 1, , , 1 2 10, , , .
Oracle , , , - . , , , , , .
minvalue maxvalue , . () , :
ORA-08004: sequence < >. NEXTVAL exceeds MAXVALUE and cannot be instantiated
cycle, , . cache . , , . . . , , .
, create sequence order, Oracle , ( ), . , , , .
: nextval currval . currval , nextval. , currval .
( , , , ) select... from dual:
select seq_emp.currval from dual
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ORA-08002: sequence SEQ_EMP.CURRVAL is not yet defined in this session
select seq_emp.nextval from dual
, , . , .
create synonym:
create [ public ] synonym < > for < >
drop:
drop synonym < >
rename: rename < > to < >
Oracle Database XE , , . ARCHIVELOG , , . , (.. ) . Oracle Database XE .