TEXT field in Blob Space vs Table Space
Hello all, I'm creating a table that has a TEXT field. When asked where the blobspace should reside I choose the table space. Any query on this table is extreamly slow (about 800,000 records). I was wondering if the table would have been quicker if I would have stored that field in a Blob Space. I had a blobspace created on our filesystem and was trying to do a speed test between the two choices but I got a -603 error when using the TEXT field that uses the blob space and I figured I would just ask before I go through all the trouble of seeing what is wrong with our blob space if it is not needed. Thanks, Richard Krenek
Richard Krenek wrote: > Hello all, > I'm creating a table that has a TEXT field. When asked where the > blobspace should reside I choose the table space. Any query on this > table is extreamly slow (about 800,000 records). I was wondering if the > table would have been quicker if I would have stored that field in a > Blob Space. In theory, it should be faster, especially for queries that do not involve the Text field, simply because the data row size has, effectively, reduced. Even when the query involves the text field, because Informix can now get two disks to supply it data simultaneously, the query should run faster. However, you must make sure that the Blobspace is actually on a different physical disk from the dbspace in which the table is. If not, query performance when retrieving data including the text field could be worse than if the text was kept in the table's dbspace. I suppose this is because the disk gets saturated by requests to retrieve data from two significantly different locations (excessive head movement). > I had a blobspace created on our filesystem and was trying > to do a speed test between the two choices but I got a -603 error when > using the TEXT field that uses the blob space and I figured I would just > ask before I go through all the trouble of seeing what is wrong with our > blob space if it is not needed. No ideas on the 603 error. Rudy