| | 72 | |
| | 73 | == dvoToMySQL == |
| | 74 | |
| | 75 | For the special case where we have a 'locked' DVO database, i.e. one that is complete and will not grow any further, we can improve ippToPsps processing time by first generating MySQL tables that include all detection from DVO rather than just the detections-per-exposure (or stack) as above. For this we can use the dvoToMySQL tool. |
| | 76 | |
| | 77 | It may take a matter of days to convert a relatively small DVO database to MySQL, however, querying the MySQL database is hugely faster than accessing DVO directly, especially for regions of sky with a high density of detections, such as the medium deep fields. (This was seen when loading MD4 prior to the Boston meeting in May 2011. DVO access per exposure was 40 minutes, whereas, once imported to MySQL, query time was roughly 30 seconds.) |
| | 78 | |
| | 79 | === Image ID confusion == |
| | 80 | |
| | 81 | We access DVO via a combination of 'source ID' and 'image ID'. Both numbers come from the smf file. However, {{{IMAGE_ID}}} in the smf does not correspond to {{{IMAGE_ID}}} in DVO, instead, it maps to {{{EXTERN_ID}}} in the Images.dat file at the top-level of a given DVO database. The {{{IMAGE_ID}}} column of the same table maps instead to {{{IMAGE_ID}}} in the various 'cpm' (''measurements'') files contained within the subdirectories of the same DVO database. |
