Re: [sqlite] group_concat for binary?
Well, I didn't think BLOB stores text more efficiently. It's just that my data is actually in binary. To store it in text I'll have to encode it, which thus require twice storage as large. Anyway, I've managed to create my own custom aggregate function to accomplish this. The initial results look fine. I'll post again if I ran into troubles. Best regards, He Shiming -- From: "John Stanton" <[EMAIL PROTECTED]> Sent: Monday, March 10, 2008 12:24 PM To: "General Discussion of SQLite Database" <sqlite-users@sqlite.org> Subject: Re: [sqlite] group_concat for binary? > Why do you think a BLOB stores text more efficiently? Do you compress it? > > He Shiming wrote: >> Hi, >> >> I would like to know if there is some workaround to use group_concat on >> binary columns. >> >> For performance consideration, I need to query two tables and accomplish >> data retrieval in a single SELECT. There is this BLOB column, originally >> designed as BLOB rather than text so that the storage is efficient. So >> can I >> use group_concat to join binary columns? I don't know if the >> implementation >> actually treats the output column as a string, or it will determine the >> actual length, in which case, it might be possible. >> >> What choices do I have? Is it a good idea to add another column that >> contains the encoded text representation of the BLOB? >> >> Thanks in advance, >> He Shiming >> >> ___ >> 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
Re: [sqlite] group_concat for binary?
Why do you think a BLOB stores text more efficiently? Do you compress it? He Shiming wrote: > Hi, > > I would like to know if there is some workaround to use group_concat on > binary columns. > > For performance consideration, I need to query two tables and accomplish > data retrieval in a single SELECT. There is this BLOB column, originally > designed as BLOB rather than text so that the storage is efficient. So can I > use group_concat to join binary columns? I don't know if the implementation > actually treats the output column as a string, or it will determine the > actual length, in which case, it might be possible. > > What choices do I have? Is it a good idea to add another column that > contains the encoded text representation of the BLOB? > > Thanks in advance, > He Shiming > > ___ > 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] group_concat for binary?
Hi, I would like to know if there is some workaround to use group_concat on binary columns. For performance consideration, I need to query two tables and accomplish data retrieval in a single SELECT. There is this BLOB column, originally designed as BLOB rather than text so that the storage is efficient. So can I use group_concat to join binary columns? I don't know if the implementation actually treats the output column as a string, or it will determine the actual length, in which case, it might be possible. What choices do I have? Is it a good idea to add another column that contains the encoded text representation of the BLOB? Thanks in advance, He Shiming ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
