t: RE: [firebird-support] Not Exists cost
> If B_TABLE.VALUE2 never contains 'X' and half of A_TABLE.VALUE1 are 'Y'
> what would be the cost of executing this statement? A_TABLE.VALUE1 is
> indexed and B_TABLE.VALUE2 does not have an index.
>
>
To: firebird-support@yahoogroups.com
Subject: Re: [firebird-support] Not Exists cost
>> SELECT *
>> FROM A_TABLE at
>> WHERE
>> at.VALUE1 = 'Y' AND
>> NOT EXISTS (
>>SELECT 1
>>FROM B_TABLE bt
>>WHERE bt.VALUE2 = 'X');
&
: Monday, April 02, 2012 5:13 PM
To: firebird-support@yahoogroups.com
Subject: RE: [firebird-support] Not Exists cost
> If B_TABLE.VALUE2 never contains 'X' and half of A_TABLE.VALUE1 are
'Y'
> what would be the cost of executing this statement? A_TABLE.VALUE1 is
> in
>> SELECT *
>> FROM A_TABLE at
>> WHERE
>> at.VALUE1 = 'Y' AND
>> NOT EXISTS (
>>SELECT 1
>>FROM B_TABLE bt
>>WHERE bt.VALUE2 = 'X');
>
> The query PLAN would tell you for certain, but I would expect the answer to
> be:
> half of A_TABLE rows times all of B_TABLE rows.
If there'
> If B_TABLE.VALUE2 never contains 'X' and half of A_TABLE.VALUE1 are 'Y'
> what would be the cost of executing this statement? A_TABLE.VALUE1 is
> indexed and B_TABLE.VALUE2 does not have an index.
>
> Would it be half of A_TABLE rows times all of B_TABLE rows? Or would the
> Not Exists stateme
If B_TABLE.VALUE2 never contains 'X' and half of A_TABLE.VALUE1 are 'Y'
what would be the cost of executing this statement? A_TABLE.VALUE1 is
indexed and B_TABLE.VALUE2 does not have an index.
Would it be half of A_TABLE rows times all of B_TABLE rows? Or would
the Not Exists statement be evalua
