Learn Oracle at your Home

Learn Oracle at your Home

Oracle DBA online training will give you the through and in-depth knowledge on each and every topics of our Oracle training curriculum. Our Oracle DBA online training is designed with the help of our expert trainers. They made the total syllabus of our OracleDBA training to cop up with the latest challenges.

Learn Golden Gate with the Concept of Primary Key:

It supports tables with and without any primary key. But if you are replicating or making copy of tables that donot have a primary key, then there are some vital factors you need to consider.

Take a sample table, created as follows:

create table sizetest (idno number, data1 varchar2(50), data2 varchar(4000), data3 varchar2(50), data4 varchar2(30));

alter table sizetest add constraint pk_sizetest primary key (idno);

This table maybe overemphasis the problem; because it has several number of character columns (here data1, data2, data3 and data4) but this is often the case with the real world data.

Consider this one:

create sequence seqsizetest;

begin
for counter in 1..20000
loop
insert into sizetest values (
seqsizetest.nextval,
dbms_random.string('B',dbms_random.value(0,50)),
dbms_random.string('C',dbms_random.value(0,4000)),
dbms_random.string('D',dbms_random.value(0,50)),
dbms_random.string('E',dbms_random.value(0,30)));
end loop;
commit;
end;
/

Here the table ends up being with 560MB in size, and the size of the primary key is 4MB.
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How is the performance on the target database:

Another anxiety is – how the data is applied on target. Our non-Primary Key source updatequitted quickly. This was a set based operation operated on the top 1000 rows of the table and then just took a second or two seconds to run. On the target yet, it will be a different difficulty entirely.

This replication is going to run 1000 discrete update statements.

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