D.19 RDB$INDICES

RDB$INDICES stores definitions of both system- and user-defined indexes. The attributes of each column belonging to an index are stored in one row of the table RDB$INDEX_SEGMENTS.

Column Name Data Type Description
RDB$INDEX_NAME CHAR(63) The unique name of the index specified by the user or automatically generated by the system
RDB$RELATION_NAME CHAR(63) The name of the table to which the index belongs. It corresponds to an identifier in RDB$RELATION_NAME.RDB$RELATIONS
RDB$INDEX_ID SMALLINT The internal (system) identifier of the index
RDB$UNIQUE_FLAG SMALLINT Specifies whether the index is unique: 0 - not unique 1 - unique
RDB$DESCRIPTION BLOB TEXT Could store comments concerning the index
RDB$SEGMENT_COUNT SMALLINT The number of segments (columns) in the index
RDB$INDEX_INACTIVE SMALLINT Indicates whether the index is currently active: 0 - active 1 - inactive
RDB$INDEX_TYPE SMALLINT Distinguishes between an expression index (1) and a regular index (0 or null). Not used in databases created before Firebird 2.0; hence, regular indexes in upgraded databases are more more likely to store null in this column
RDB$FOREIGN_KEY CHAR(63) The name of the associated Foreign Key constraint, if any
RDB$SYSTEM_FLAG SMALLINT Indicates whether the index is system-defined or user-defined: 0 - user-defined 1 or greater - system-defined
RDB$EXPRESSION_BLR BLOB BLR Expression for an expression index, written in the binary language representation (BLR), used for calculating the values for the index at runtime.
RDB$EXPRESSION_SOURCE BLOB TEXT The source code of the expression for an expression index
RDB$STATISTICS DOUBLE PRECISION Stores the last known selectivity of the entire index, calculated by execution of a SET STATISTICS statement over the index. It is also recalculated whenever the database is first opened by the server. The selectivity of each separate segment of the index is stored in RDB$INDEX_SEGMENTS.