In the process of work to reduce memory-exceeded errors and timeouts, James changed a single large meta WP_Query into a foreach loop of one-post-each meta queries. It may well be that this is a performance improvement, or that its impact depends on the environment (eg the presence or absence of memcaching), but it's also possible that this will cause issues with SQL. We should set some timers and count the execution time necessary for the same import conditions under both options.
In the process of work to reduce memory-exceeded errors and timeouts, James changed a single large meta WP_Query into a foreach loop of one-post-each meta queries. It may well be that this is a performance improvement, or that its impact depends on the environment (eg the presence or absence of memcaching), but it's also possible that this will cause issues with SQL. We should set some timers and count the execution time necessary for the same import conditions under both options.