topic Re: Left outer join in Application Development and Automation Discussions

Left outer join

sanju_joseph — Tue, 03 Feb 2009 15:49:31 GMT

Hi,

How to avoid left outer join , like in case of inner join we use 'select for all entries' and read statement,

how can we acheive the same for left outer join case , please provide the explanation with example

Regards,

Sanju

Re: Left outer join

ThomasZloch — Tue, 03 Feb 2009 16:56:00 GMT

Sounds purely academic to me, please provide explanation why you want to avoid (left) joins in the first place.

Thomas

Re: Left outer join

sanju_joseph — Wed, 04 Feb 2009 05:35:01 GMT

Hi,

In one of our program they have used left outer join to join 6 tables, I have seen

time taken is more , to avoid this i break this into loops within

loop and found that time taken is small ,but the count of the record got increased for

the missing value on some column,it seems like i am doing something wrong,

so example to avoid left join will be higly appreciated.

Regards,

Sanju

Re: Left outer join

ThomasZloch — Wed, 04 Feb 2009 08:03:28 GMT

Please post the Join statement here for analysis, because I suspect that the performance problem might not be the join in itself but rather missing index support. If Z-tables are involved, also post their primary and secondary indexes.

Thomas

Re: Left outer join

Former Member — Thu, 05 Feb 2009 05:00:32 GMT

Hi Sanju Joseph,

You can avoid the Left outer join when you dont want the null values from the right table.

For example,

Left table is : SPFLI

Right table is : SFLIGHT.

If you want the common data without getting the null values from the table SFLIGHT y becoz left outer join gets the null values from the right table when a partiucular record is not matching.

So , if u dont want those unneccessary values into your table then you can avoid the left outer join.

Regards

Kiran