2011/10/25 Bo Peng <ben....@gmail.com>: > Tables are added in batch and then kept unchanged. I mean, a database > might have 1000 new tables one day, and 2000 later. All operations are > on single tables. > > Each table is for one 'sample'. All tables have one column for 'item > id', and optional (zero - perhaps 6) columns for item attributes, > which can be INT or FLOAT.
Is your 'id' type INTEGER PRIMARY KEY? Each table in SQLite have a hidden key 'rowid INTEGER PRIMARY KEY'. You may merge it with 'id'. > There is no index and no key because I was concerned about insertion > performance and size of database. My understanding is that index or > key would not help simple aggregation operations because all records > will be iterated sequentially. If you do not need indexes, you can use a simpler solution: CSV. One sample (now a table) -> one CSV file. Searching will be faster. > I am running SELECT COUNT(*), MAX(QT) FROM TABLE_XX; etc as long as > the WHERE clause is the same. You can create additional indexes after inserting data into a table. To search for maximum serve well. If the content of tables also constant, it is possible after a creating to generate the aggregated values? For additional search would only use this summary data. -- Kit _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
