thanks!
On Jun 18, 2009, at 6:01 PM, Dennis Cote wrote: > James Gregurich wrote: >> on that update statement, is the SQL optimizer smart enough to not >> rerun that select statement for each column in the update's set >> clause? Is it going to run a single select statement to get <value1>, >> <value2>, etc. or is it going to run one for each column in the >> update statement? >> >> > James, > > No, I don't believe the optimizer is that smart. SQLite will execute > multiple queries. > > If you are concerned that the matches table is large you could add an > index on the the row1 column of the matches table to speed up the row2 > lookups. The lookups in table2 using the rowid should be very fast, > and > once the page with the required record has been read into the cache > the > subsequent value lookup queries > should execute very quickly as well. > > HTH > Dennis Cote > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
