Cl�vis Wichoski wrote: > All tables in my system have one PRIMARY KEY field of type > VARCHAR(8), if > change all fields to VARCHAR(16), how the performance of > database will be affected?
What answer do you expect? Your rows will be a little bit longer (8 bytes). If your rows have been 24 bytes before, your table will increase its size by 1/3. if your rows have been 6000 bytes before, forget the difference. If a row needs more space, you will need more pages to store the table. If your table will fit in the datacache and will remain there --> no additional I/O when it has been read once. In any other case a little bit more I/O will be done or 1/3 more I/O (see above). Your indexes will need more space. Depending on the size of your secondary key,... same as above. Short answer: it depends. Searching the table will not be faster than before. But usually you will not be able to measure the time difference. Elke SAP Labs Berlin _______________________________________________ sapdb.general mailing list [EMAIL PROTECTED] http://listserv.sap.com/mailman/listinfo/sapdb.general
