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
