How to analyse existing blobs

Hi folks I've never used blobs, but now I'm helping to resize and reorganize an engine. How do I get a dump of the sizes of existing blobs used in their live data? I want to work out a decent pageunit to use to optimise space and time on the bulk of their blobs thanks in advance. oh - another Q. Once we've created a blob space, what's the trick (if any) for relocating their existing in-table blobs out to a blobspace? Just a simple application of the ALTER TABLE command in the expected manner?

Andrew Hamm wrote: > I've never used blobs, but now I'm helping to resize and reorganize an > engine. > > How do I get a dump of the sizes of existing blobs used in their live data? > I want to work out a decent pageunit to use to optimise space and time on > the bulk of their blobs SELECT blobid, LENGTH(blob_col) FROM blobby_table; You might need OCTET_LENGTH for byte blobs; LENGTH should be correct for TEXT blobs. (I've not checked the manual to see what it says about this.) > oh - another Q. Once we've created a blob space, what's the trick (if any) > for relocating their existing in-table blobs out to a blobspace? Just a > simple application of the ALTER TABLE command in the expected manner? Sounds plausible, doesn't it...I see nothing in the manual to indicate otherwise, but it isn't an in-place alter, and it might not be all that fast! -- Jonathan Leffler #include <disclaimer.h> Email: jleffler@earthlink.net, jleffler@us.ibm.com Guardian of DBD::Informix v2003.04 -- http://dbi.perl.org/

Jonathan Leffler wrote: > Andrew Hamm wrote: >> I've never used blobs, but now I'm helping to resize and reorganize >> an engine. >> >> How do I get a dump of the sizes of existing blobs used in their >> live data? I want to work out a decent pageunit to use to optimise >> space and time on the bulk of their blobs > > SELECT blobid, LENGTH(blob_col) FROM blobby_table;> > You might need OCTET_LENGTH for byte blobs; LENGTH should be correct > for TEXT blobs. (I've not checked the manual to see what it says > about this.) great - thanks. TFM didn't mention anything about this when I checked the index for all BLOB and BYTE sections. Tut Tut. >> oh - another Q. Once we've created a blob space, what's the trick >> (if any) for relocating their existing in-table blobs out to a >> blobspace? Just a simple application of the ALTER TABLE command in >> the expected manner? > > Sounds plausible, doesn't it...I see nothing in the manual to indicate > otherwise, but it isn't an in-place alter, and it might not be all > that fast! that's fine, the alternative is an unload/reload with the consequences of that I guess. Thanks.