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I have a table of about 500,000 rows. I need to add a new column and populate it. So, I have tried to run the following command. The command
never finishes (I gave up after about and hour and a half!). Note that none of the columns have indexes. Update mytable set new_column = case when column_1 = column_2 then
1 when column_1+column_3= column_2 and column_3 > 0 then
2 when column_1+column_3+column_4 = column_2 and column_4 >
0 then 3 when column_1+column_3+column_4+column_5 = column_2 and
column_5 > 0 then 4 else 0
end My computer is a Pentium 4 – 2.4 GHZ and 1G RAM – so it
should be fast enough. Any ideas? Jonathan Blitz -- |
