Databases Reference
In-Depth Information
Columns
The Columns tab (Figure
12-13
) allows you to manage columns in the table. Columns can be added or deleted. Once
a column is created, its data type cannot be changed. To delete a column, select any column other than the indexed
column and click the Delete button at the bottom of the portal. Columns can be added in either of two ways—first, by
dropping and re-creating the table (not recommended, because of the loss of data), or second, by sending from the
application an insert request that includes the new property. To do this, Dynamic Schema must be enabled.
Figure 12-13.
The Columns tab
This tab also allows you to define indexes on the table. By default, an index is placed on the
id
column, but
columns can be added to the index to improve query performance. To add a column to the index, select the column
and click Set as Index. Columns used regularly in queries for sorting or filtering should be included in the index. Be
careful not to add too many columns to the index; this can be detrimental to performance. There are many tools
available, including SQL Server Management Studio, that allow you to examine queries that are hitting the database to
help determine which columns in the table would be beneficial to add to the index.
Permissions
The Permissions tab provides the ability to define who has Insert, Update, and Delete permissions. As shown in
Figure
12-14
, there are four options:
