Reference Manual
CHAPTER 15. System Tables
Column name |
Column type |
Column constraint |
Table constraints |
|---|---|---|---|
table_id |
SMALLINT |
NOT NULL |
Primary key, foreign key references SYS.SYSCOLUMN |
index_id |
SMALLINT |
NOT NULL |
Primary key, foreign key references SYS.SYSINDEX |
sequence |
SMALLINT |
NOT NULL |
Primary key |
column_id |
SMALLINT |
NOT NULL |
|
"order" |
CHAR(1) |
NOT NULL |
Every index has one row in SYSIXCOL for each column in the index.
table_id Identifies the table to which the index applies.
index_id Identifies in which index this column is used. Together, table_id and index_id identify one index described in SYSINDEX.
sequence Each column in an index is assigned a unique number starting at 0. The order of these numbers determines the relative significance of the columns in the index. The most important column has sequence number 0.
column_id The column number identifies which column is indexed. Together, table_id and column_id identify one column in SYSCOLUMN.
order (A/D) Indicate whether this column in the index is kept in ascending or descending order.