Well I need to have the new columns for subsequent processing of the data. I have some complex functions that I need to use to modify the existing data into the new columns. I don't think I can do that with user-defined functions within the select command itself. Does that make any sense?
----- Original Message ----- From: "Greg Morphis" <[EMAIL PROTECTED]> To: "General Discussion of SQLite Database" <sqlite-users@sqlite.org> Sent: Tuesday, August 19, 2008 1:01 PM Subject: Re: [sqlite] 2 Questions from a newbie > Also why are you adding new columns? doesn't sound like you have the > db set up properly.. > > On Tue, Aug 19, 2008 at 11:53 AM, cstrader <[EMAIL PROTECTED]> > wrote: >> OK, cool idea... let me try that. >> >> >> ----- Original Message ----- >> From: "Jeff Hamilton" <[EMAIL PROTECTED]> >> To: <[EMAIL PROTECTED]>; "General Discussion of SQLite Database" >> <sqlite-users@sqlite.org> >> Sent: Tuesday, August 19, 2008 12:51 PM >> Subject: Re: [sqlite] 2 Questions from a newbie >> >> >>> If all 2,400 tables have the same 9 columns you could try using a >>> single table and adding a column for the ticker of the stock and then >>> add an index to that column to allow quick lookups based on the >>> ticker. >>> >>> -Jeff >>> >>> On Tue, Aug 19, 2008 at 9:44 AM, .:UgumugU:. <[EMAIL PROTECTED]> wrote: >>>> Hi cstrader, >>>> >>>> Just send some table structure and the explain what you are trying >>>> todo. >>>> In my opinion it is not a good way to deal with 2400 tables :) >>>> >>>> ugumugu >>>> >>>> cstrader yazm?s,: >>>>> I'm just starting with SQLite (from vb.net) and could use some advice. >>>>> >>>>> I have a set of 2400 (could get substantially higher) tables in a >>>>> single >>>>> database (each table contains daily stock prices for a different >>>>> stock). >>>>> Each table has 9 columns (all text for now) and some several thousand >>>>> rows. >>>>> So far so good. >>>>> >>>>> I need to read those tables sequentially and operate on them. It >>>>> takes >>>>> about 18 seconds to open each of the tables in sequence. (i.e. loop >>>>> through 2400 tables with a select command opening each one) >>>>> >>>>> First question... does that sound about right in terms of speed? Is >>>>> there a >>>>> way to store the data that might be faster? The data are primarily >>>>> single >>>>> precision -- I'm using text format, but perhaps that's not best? >>>>> >>>>> Second question: >>>>> >>>>> When I open each table I need to add some blank columns to it. So I >>>>> include >>>>> some "0 as NewCol" lines to create the new columns with initial 0s. >>>>> >>>>> However, adding 20 new columns in this manner increases the total time >>>>> for >>>>> the loop from 19 seconds to 49 seconds. This seems like a long time. >>>>> Is >>>>> there a faster way to get these empty columns in? >>>>> >>>>> More questions later I'm sure... >>>>> >>>>> Thanks in advance >>>>> >>>>> cs >>>>> >>>>> _______________________________________________ >>>>> sqlite-users mailing list >>>>> sqlite-users@sqlite.org >>>>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >>>>> >>>>> >>>> >>>> _______________________________________________ >>>> sqlite-users mailing list >>>> sqlite-users@sqlite.org >>>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >>>> >>> _______________________________________________ >>> sqlite-users mailing list >>> sqlite-users@sqlite.org >>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> >> _______________________________________________ >> sqlite-users mailing list >> sqlite-users@sqlite.org >> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
