Re: Sv: Oracle SQL engine?

But I got error in one of the select in statement

Allan Saadbye <isl34485_at_image.dk> wrote:
: Hey Johnnie,

: There are no differences between your 2 'selects'.

: The first 'select a.*' means that you want the entire table 'dual a'
: displayed.

: On the other hand is very usefull if you have to related table where you
: only want to
: display some information.

: Norris <johnnie_at_cooper.com.hk> skrev i en
: nyhedsmeddelelse:7o6siq$kto$1_at_imsp009a.netvigator.com...

:> Can anybody tell me the differences between the following two SQL?
:>
:> select a.* , dummy from dual a
:> /

: sql>select a.start_date,b.emp_name from project a,emp b
: sql>where a.emp_id=b.emp_id

: Could show you all the project startdates that have been initaiated by
: each employee.

: It dosn't have to be 'a,b,c etc' but could also be 'me, loan, others'.

:> select * , dummy from dual a
:> /
:>
:> --
:> ===================================
:> http://www.washington.edu/pine/faq/

: If you are running vldb you should be carefull to join tables like this,
: hence you could
: set the proccesor in progress of many hours at work.

: Some little advice :

: Table a = 10.000 records
: Table b = 5.000.000 records
: Table c = 10.000.000.000 records

: A 'select * from table a,table b, table c' should be interpetreted as a
: request that is
: 10.000 multiplied 5.000.000 multiplied 10.000.000.000, which is BIG number.
: For some reason only Oracle can answer this 'select' is slower than :
: select * from table c,table b, table a. I think its because of the
: Oracle/sql compiler.

: Do visit http://www.orcmag.com.code.tip06049.html>

: with regards Allan

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