INDEXES: Create Index -- Infopops

Select a schema for the index that you are creating. The initial value in this box is the user ID under which you connected to the database.

Type a name for the index that is 1 to 18 characters, and does not include its qualifier. The name can be an ordinary or delimited identifier. The name must be unique within the index's schema.

Select the schema of the table on which you are creating and index. The initial value in this box is the user ID under which you connected to the database.

Type the name of the table on which the index is created. The table must be a base table (not a view) described in the catalog. It must not be a catalog table.

This list box lists all of the columns defined for the table specified in the Table name field. Use this box to select the column or columns that you want to define as part of the index key. You can select one or more columns at the same time.

Moves the selected items from the Available columns list to the Selected columns list. This button is only active if you are creating an index.

Moves all columns displayed in the Available columns list box to the Selected columns list box.

Moves selected columns in the Selected columns list box to the Available columns list box.

Move all columns displayed in the Selected columns list box to the Available columns list box.

Use this box to specify additional columns to be included in the index but not as part of the unique index key. These columns may improve the performance of some queries through index-only access. The columns must be distinct from the columns used to enforce uniqueness.

To add a column name to this box, select it from the Available columns list box and select the > push button.

You can specify up to 16 columns. The sum of the length attributes of the specified columns must not be greater than 255 bytes.

Moves selected columns in the Available columns list box to the Include columns list box.

Moves all columns displayed in the Available columns list box to the Include columns list box.

Moves selected columns in the Include columns list box to the Available columns list box.

Move all columns displayed in the Include columns list box to the Available columns list box.

Use this box to specify the column or columns that you want to define as part of the index key.

To add a column name to this box, select it from the Available columns list box and select the > push button.

You can specify up to 16 columns. At least one column must be specified to define an index.

The sum of the length attributes of the specified columns must not be greater than 255 bytes.

Click on this push button to move the selected object up one position in the list box.

Click on this push button to move the selected object down one position in the list box.

Use this radio button to specify the sort order of the columns that you selected in the Selected columns list box.

Use this radio button to specify the sort order of the columns that you selected in the Selected columns list box.

Lists any columns to be included as part of the index but not to be included as part of the unique index key. These columns can improve the performance of some queries through index-only access. Use the <<, <, >, and >> buttons to add and remove columns from this list. You can specify up to 16 columns, but the sum of their length attributes must not be greater than 255 bytes.

Click on this push button to move the selected object up one position in the list box.

Click on this push button to move the selected object down one position in the list box.

Use this radio button to specify the sort order of the columns that you selected in the Include columns list box.

Use this radio button to specify the sort order of the columns that you selected in the Include columns list box.

When the Unique check box is selected, null values are treated as any other values. For example, if the key is a single column that can contain null values, that column can contain no more than one null value.

Select to specify that the index that you are creating is to be the clustering index of the table. A clustering index will influence the way data is physically stored by causing new table entries to be places so the the organization of the data mirrors that of the index as much as possible. This option is only available if there is not already a clustering index for the table, if the index is not set to append mode.

Select to allow the index to support scans both in the order defined when the index was created, and in the reverse order. Reverse scans eliminate the need for the optimizer to create temporary tables for reverse scans, and eliminate the need to create a second index for conducting reverse scans. It also facilitates determination of the maximum key of an index. If you do not allow reverse scans, the index will support scanning only in the order defined at the time the index is created.

This field specifies, for Online Index Reorganization, the threshold for the minimum percentage of used space on an index leaf page. If the percentage of space used on the page is at or below integer % after a key is deleted from an index leaf page, an attempt will be made to merge the remaining keys on this page with those of a neighbouring page. If there's sufficient space on one of these pages, the merge will be performed and one of the pages will be deleted.

The value of integer can be from 0 to 99. However, a value of 50 or below is recommended for performance reasons. The default value is 10 percent.

Enter the minimum percentage of space that should be used on any index page. An index page that falls below this threshold will cause the database to attempt an Online Index Reorganization, which causes the index page to merge with one of its adjacent pages if there is enough free space to allow it.

You can enter any value between 0 and 99. A value less than 50 is recommended for performance reasons. The default value is 10.

Type a comment to document the index that you are creating or altering. You can type up to 254 characters, including embedded blanks.

Performs the actions that you have specified in this notebook or window.

Cancels any unsaved changes that you made and closes this notebook or window.

Opens the Show SQL window.

Opens the Estimate Size window, in which you can estimate the amount of storage space for a new or existing table or index.