Hi John, If you are worried about the naming, you could call the function "serialize" because that is essentially what you are doing: serializing the table to disk. I wouldn't use "dump" because you are already using that to dump stuff to the screen and you could confuse people.
Can the user set an alias for a column name? That would certainly be one way to deal with the SUM(a) issue. You could also allow the user to rename the column name before writing it out. If they don't do that, then you could just change bad characters to good ones...You might also want to get rid of spaces....would SUM(a) and SUM( a ) be written as different column names? Regards, Teryl On Wed, Apr 7, 2010 at 3:36 PM, K. John Wu <[email protected]> wrote: > Hi, Teryl, > > Good points. Thanks for your offer to help with testing. I should be able > to get around to implement something in a day or two. > > Regarding the possiblity of using the tablex interface, my concern is not > to make the table object extensible, but simply to write it. Seems like just > having a write function is a little better. The concern is that it might > clash with a future class that derives from both table and tablex. In this > case, the solution might be to use a different function name, say, backup or > dump, instead of write. Any comments? > > Regarding the column names, since a column name like 'sum(a)' is not usable > in future queries -- it will be interpreted as a function on column named a. > We will have to rename them to something else. If there is an alias for it > already in the select clause, it will be used, otherwise, it will be up to > us to rename it to something else. One suggestion is simply to change all > characters that are not allowed in a SQL column name to be the underscore > character _. Anyone has a better suggestion? > > John > > > > On 4/7/2010 11:12 AM, Teryl Taylor wrote: > >> Hi John, >> >> You might be able to create a constructor on the ibis::tablex object >> which takes an ibis::table and then just use the write function on >> tablex if you want to keep the read/write separated between the two >> objects. But some sort of a write function like in tablex should work >> well. How would you handle columns that are made up of an aggregate >> function...so for instance SUM(A). Would the column on disk just be >> called SUM(A)? >> >> Let me know if/when you do implement something like this, I can >> probably help test it for you. I'm writing a little tool that does >> queries out of a set of partitions, and it would be great to be able to >> drop the results into a temporary partition and then read that partition >> or join as needed. >> >> Best Regards, >> >> Teryl >> >> >> >> On Tue, Apr 6, 2010 at 8:38 PM, K. John Wu <[email protected] >> <mailto:[email protected]>> wrote: >> >> Hi, Teryl, >> >> Good point. The functionality of writing out an existing table is >> not there and will be added shortly. I am planning to use the same >> function name and prototype as ibis::tablex::write. Do you have any >> comment or suggestion? >> >> John >> >> >> >> On 4/6/2010 12:09 PM, Teryl Taylor wrote: >> >> Hi, >> >> I am doing my queries on a list of partitions using the select >> method on >> an ibis::table object. Is there an easy way to take the new table >> returned from a select or groupby method, and write it to a >> temporary >> partition or set of partitions on disk? >> >> >> Regards, >> >> Teryl >> >> >> >> _______________________________________________ >> FastBit-users mailing list >> [email protected] <mailto:[email protected]> >> >> https://hpcrdm.lbl.gov/cgi-bin/mailman/listinfo/fastbit-users >> >> >>
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