These limits apply to indexes in Adaptive Server:
Because the data for a cluster index is ordered by index key, you can create only one clustered index per table. Adaptive Server creates a clustered index by default as a local index for range-, list-, and hash-partitioned tables. You cannot create global clustered indexes on range-, list-, or hash-partitioned tables.
You can create a maximum of 249 nonclustered indexes per table.
When you create a clustered index, Adaptive Server requires empty free space to copy the rows in the table and allocate space for the clustered index pages. It also requires space to re-create any nonclustered indexes on the table.
The amount of space required can vary, depending on how full the table’s pages are when you begin and the space management properties are applied to the table and index pages.
See “Determining the space available for maintenance activities” in “Database Maintenance,” in Performance and Tuning Series: Physical Database Tuning.
The referential integrity constraints unique and primary key create unique indexes to enforce their restrictions on the keys. By default, unique constraints create nonclustered indexes and primary key constraints create clustered indexes.
A key can be made up of as many as 31 columns. The maximum number of bytes per index key is varies by the page size in bytes as follows:
Page Size |
Max key length |
|---|---|
2048 |
600 |
4096 |
1250 |
8192 |
2600 |
16384 |
5300 |
