On 20 Dec 2017, at 3:38pm, Nelson, Erik - 2 <erik.l.nel...@bankofamerica.com> wrote:
> Assuming that table 'data' is completely constructed, does index creation > order have any performance ramifications? > > For example, would it be reasonable to assume that the order of these two > statements has no performance impact? (all fields are integer in this case) > > create unique index data_index_1 on path_data(id, path, date) > create index data_index on data(path, date) The 'id' column is unique. And as id is also the primary key of the table (assuming you’re doing things the normal way) there’s already a UNIQUE index made on it. So there’s no point in creating the first index. As a general rule, once you have created all your indexes, the order in which indexes were created makes no difference to timing for future operations. Once you have created all your indexes, and populated your tables with plausible data, run ANALYZE. Although you can do this with empty tables, it can gather far more useful information once it sees the sort of data you put in your tables. Once you’re run ANALYZE once there’s no need to run it again unless you change your schema or radically change the kind of data stored in you tables. Simon. _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
