On the other hand, many experienced database designers will argue that a well-normalized database will never need more than 100 columns in a table. You can change it at compile time to values as large as 32767. We've now moved the Blob into its own table, and our app is happy. As specified in Limits In SQLite: The default setting for SQLITEMAXCOLUMN is 2000. The DEFAULT constraint allows you to specify a value to be used in the event no value is supplied for that column when a new row is inserted. Once the view is created, it can be used in the FROM clause of another SELECT in place of a table name. Description The CREATE VIEW command assigns a name to a pre-packaged SELECT statement. view-name ( column-name ) AS select-stmt, select-stmt: 2.
One such constraint is the DEFAULT constraint. Syntax create-view-stmt: CREATE TEMP TEMPORARY VIEW IF NOT EXISTS schema-name. Massive difference, and the reason is because of the Blob filesize is before the Blob and basicScanStatus is after. When creating a table in SQLite, you have the option of adding constraints to each column. Time sqlite3 Catalog.db 'select count(*) from SomeItems where basicScanStatus = 2 'ĭoes not matter how many records are returned, on my machine, the first query takes about 0m0.008s and the second query takes 0m0.942s. Then do a couple of queries like this: time sqlite3 Catalog.db 'select count(*) from SomeItems where filesize = 2 '
Populate the table with about 20,000 records where thumbnail is a small jpeg. Conceptually, it shouldn't, but try this experiment to prove that it does: CREATE TABLE SomeItems (įilename TEXT NOT NULL, path TEXT NOT NULL,įilesize INTEGER NOT NULL, thumbnail BLOB,
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