Zavier Sheran wrote: > > I have a VARCHAR(2000) column in a table that is not needed in any WHERE > clause. Can I imporove perofmance by declaring it a LONG column (in case > LONG columns are stored apart from the other columns)? >
As so often: it depends. If your LONG/VARCHAR-column usually is part of the select-list, then you need more I/0 for accessing the normal columns + the LONG-column stored separately than when you just access the record incl. your VARCHAR-column. If your column is needed very rarely, a LONG-column would be better as its absence will shorten the normal record. If your column is usually filled up to the full length, it does not matter (for the communication between client and server) if it is a LONG-column or a VARCHAR-column. If usually only fewer bytes are filled, then you should know that the VARCHAR-column will be transferred between server and client with its definition-length of 2000, not only with the really needed length. LONG-columns need the really needed value-length + some bytes overhead, often (even together) shorter than the definition length. Elke SAP Labs Berlin > -Zavier -- MaxDB Discussion Mailing List For list archives: http://lists.mysql.com/maxdb To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
