Re: crosstab

>
> (what btw forced me to check it in plv8 - and it seems they use the same
> approach internally in behind :( - though doesn't make sense because of
> find_function works just with plv8 postgres functions)

Just realised I have called wrong method - so above is not true... it
returns real v8 object, and methods of that object can be called :)

Sorry,

Misa

2012/9/5 Misa Simic <misa(dot)simic(at)gmail(dot)com>

> Hi Joe,
>
> Do you maybe know, is it possible inside PL/R to call another PL/R
> function - but take result as R object (whatever R function returns)?
>
> If we take this scenario for example (Take some data from DB, pivot them,
> and save it as CSV)... pseudo code would be:
>
> -Execute SQL query
> -pivot returned data
> -save it to CSV...
>
> of course everything could be in one function, but I would organize my
> code in much more... because of for example, if I need tomorrow get the
> same thing and save it to PDF, or Save it to graph etc... I could
> copy/paste the same function and change code in step 3... but if something
> tomorrow should be changed in step 1 or 2 - I would need to make the same
> change on 3 places... In pure R for example, I would have at least:
> getPivotedData function and then SaveToCSV would call getPivotedData() and
> save it in CSV, SaveToPdf would call the same getPivotedData() and save it
> to PDF... etc, then tomorrow if something should be changed in first two
> steps - I would change just getPivotedData function... and cover whole 3
> scenarios...
>
> Now, of course PostgreSQL function can't return R object, but plv8 has
> solved that problem as plv8 Postgres Function returns record - what is an
> v8 object...
>
> Then inside one plv8 function, we say
> plv8.find_function("myv8FunctionWhatReturnsv8Object"), call it and takes
> actuall result and do with that whatever need to be done inside v8
> environment...
>
> During I have written this mail - you have replied that actually my
> question could be acomplished with serialise/deserialise... but I am not
> sure I would take that approach - because of "methods" of an object would
> be lost during serialize/deserialize... (what btw forced me to check it in
> plv8 - and it seems they use the same approach internally in behind :( -
> though doesn't make sense because of find_function works just with plv8
> postgres functions)
>
>
> Thanks,
>
> Misa
>
>
>
>
> 2012/9/4 Joe Conway <mail(at)joeconway(dot)com>
>
>> On 09/04/2012 01:23 PM, Aram Fingal wrote:
>> > So then, PL/R is not a solution to being able to pivot tables
>> > directly in PostgreSQL but I might be able to define a PL/R procedure
>> > which, for example, pivots tables and then uses the write.table()
>> > function of R to send the results to disk without returning any rows
>> > to PostgreSQL? Such a procedure might prove be faster and more
>> > convenient than extracting the data from PostgreSQL into an R
>> > application layer and then writing to disk.
>>
>> As mentioned somewhere else along this thread, I don't know that it will
>> be faster, but it may well be more convenient if your goal is to get a
>> CSV file in the end anyway.
>>
>> Joe
>>
>>
>> --
>> Joe Conway
>> credativ LLC: http://www.credativ.us
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>>
>>
>>
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>
>