Exporting from GDX to MS Access

questions about GAMS' tools
Post Reply
Sakib2889
User
User
Posts: 2
Joined: 2 weeks ago

Exporting from GDX to MS Access

Post by Sakib2889 » 2 weeks ago

Hello,
I want to export calculated results from GDX to MS Access. But, the database limit is making it difficult to dump all 5 of my parameters into the same MS Access database. Note that MS Access database has a limit of 2 GB. Exporting my first parameter, the GAMS can export no more.
Can I dump one parameter from GDX at a time, meaning can I mention which parameter to export? Or is there better way to retrieve my data?
TIA

User avatar
bussieck
Moderator
Moderator
Posts: 832
Joined: 6 years ago

Re: Exporting from GDX to MS Access

Post by bussieck » 2 weeks ago

The tool gdx2access exports the entire content of a GDX file to MS-Access, no selection of symbols possible. The solution here would be to generate 5 different GDX files with one symbol per GDX and use gdx2access to create 5 MS-Access databases. You can also try the new GAMS Connect with agent pandasSQLWriter (https://www.gams.com/latest/docs/UG_GAM ... SSQLWRITER) that let's you write directly from GAMS to MS-Access and is highly customizable. You need a 64-bit office or at least the 64-bit MS-Access ODBC driver (explained in the docs).

-Michael

Sakib2889
User
User
Posts: 2
Joined: 2 weeks ago

Re: Exporting from GDX to MS Access

Post by Sakib2889 » 2 weeks ago

Thank you. I am really a novice in GAMS, in programming as a whole. So, I did not clearly get how I am supposed to code that into my GAMS code. For the first option, I already thought of that but I didn't want to run my optimization again as it takes time. Is there any other way I can retrieve the parameters without running the optimization again. Like is there somewhere the calculated value gets stored when we run an optimization.
Thanks for your time.

User avatar
bussieck
Moderator
Moderator
Posts: 832
Joined: 6 years ago

Re: Exporting from GDX to MS Access

Post by bussieck » 2 weeks ago

You should look at execute_unload (https://www.gams.com/latest/docs/UG_GDX ... UTE_UNLOAD). If you want to split your existing GDX file, then use "gdxdump my.gdx noData > my.gms" to create a GAMS file my.gms that reads your entire GDX file into GAMS and then have at the end of my.gms a couple of execute_unload statements, one for each symbol.

-Michael

Post Reply