I am seeing a performance issue related to schema upgrades. This is from a C++ program that uses the MAPI library. We try and keep 30 days worth of data, imported at a fairly high data rate with lots of columns. We use multiple threads to ingest data (bulk insert), and the number of threads is stored in a configuration table. For 20 days worth of data, this works out to around 9000 tables (plus merge tables). We have roughly 6 sets of tables per hour, each of which has 4 tables and a merge table connecting them. Because this is a schema change, we wrap the entire upgrade in a transaction. For the purpose of the test, we had no data in the tables, but only had empty tables. If we change our setting from 4 parallel tables to 2, we end up dropping 9000 tables. About half of the "drop table" commands take 0 seconds. The rest take anywhere between 4 and 12 seconds each. Here is a plot of the time per delete, y access is seconds, x is the statement. The X access is NOT time based: [cid:image001.png@01D5568E.A5389030] Any idea on how we can reduce the time? The total time to delete 9000 tables was 480 minutes. Thanks, Dave
