Metdb help for: Table to compare against
If you type in the name of a table (including the owner-prefix: eg u_wmc.gts_synop)
then the contents of that table will be compared against the one you have selected.
This will only work at a tolerable speed if
- The table you are comparing against is very small (this is not true of gts_synop, gts_land_synop, or
gts_ship_synop) OR
- The table you are comparing against has indexes on obtime and ident (this is true of the u_wmc tables) AND
- You select a particular ident to compare against
The SQL generated says something like "SELECT <what you asked for> WHERE obtime and id match across tables,
and <what you asked for> disagrees across tables".
What will go wrong:
- Don't try to select averaging, etc, I hate to think what might happen...
- Some tables use oracle-null for no data; some use 99.9 or somesuch; this
will look different
- Tables must have obtime and id column for the comparison to work