Hi,
RE: > we have a table with many (~0.5 billion) records and a geometry field > which was defined as a simple "point". The `show table status` shows that > the row format is dynamic, however, a simple point in the GIS > representation has a fixed format (see: WKB: 21 bytes: 1 for MSB/LSB, 4 > for type and 2x8 for the two doubles). We experienced that in this case, > when we include this point field all `select`ions and indexing (alter > table ... add [spatial] index ...) are much slower rather than if we > exclude this "point" object. I made a couple of new tests related to this. To give further examples, if the table contains a point-type column (MMpoint) at the end, selection based on another column (e.g. MMI) is about 2 to 3x slower (with or without indexing on MMI). Splitting of geometry information from the table to a separate table, and using join, greatly increases speed, especially if done on 10million or more records. All in all, it is a great pity that the geometry.point type can not be chosen as fixed "width". Gaspar -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
