Link to home
Start Free TrialLog in
Avatar of Claudio Herrera
Claudio HerreraFlag for Mexico

asked on

Microsoft Access 2002/2003 References Activex Data Objects

Dear Experts,

What is the difference between check the Microsoft Activex Data Objects 2.1 Library VS Microsoft ActiveX Data Objects 2.8 Library?

TIA

Regards,
Antonio Macias
SOLUTION
Avatar of DatabaseMX (Joe Anderson - Former Microsoft Access MVP)
DatabaseMX (Joe Anderson - Former Microsoft Access MVP)
Flag of United States of America image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
ASKER CERTIFIED SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
<ot>
Hey Leigh ... while you are here ...
Question.  I have read this:
Say you have a (Select) query in design view in the query grid ... 2-3 tables, nothing special.  You make some changes (new fields, sorting, whatever).  According to what I read ... JET optimizes the query - creates the 'plan' when you Save in design view ... against the existing data at that time ... as opposed to ... when you actually Run the query (from say the query grid)  *after* saving it.  In fact, it says that IF .... you Run the query (from the query grid) ... and then Save again ... the plan goes away.

What is the reality here?

thx.mx

<ot/>
Hi MX.
Sorry not gotten to look at this before now... just been pretty busy and don't get over to EE all that often anyway these days.

IMO saving a querydef definition results only in the SQL being parsed.  If the SQL is valid then it's committed to the definition. (It's here that nasty things can happen to well formatted SQL - especially subqueries).
Compiling and forming an optimized execution plan occur only when executing the query (that first time).
Subsequent calls to the query use that plan - until it has cause to be re-compiled (e.g. by editing the query or compacting the database).

Saving again *might* cause the plan to be removed... if Access perceives that an edit took place (generally you'd want to be pretty specific about this - making an actual edit... even if it's superficial/temporary - but saving again might be interpreted as an edit by Access).
But only upon executing the query should optimisation and plan saving occur.
Thanks Leigh.  That would be my guess also.  I think this article got it backwards, which prompted this question. My impression has always been that it occurs when 'first' run after an edit/save or compact operation. I don't see how ... until it was run against the current data set any optimization could occur. I will did up that article and review what it said.

"and don't get over to EE all that often anyway these days."
np ... more points for me , HA HA :-)  (but PLEASE - stop by when you can!!!)

thx.mx