FP_NBIT_LOOKUP_MB Option

Limits the total dictionary size for implicit NBit FP columns.

Allowed Values

1  – 4,294,967,295

Default

64MB

Scope

Option can be set at the database (PUBLIC) or user level. When set at the database level, the value becomes the default for any new user, but has no impact on existing users. When set at the user level, overrides the PUBLIC value for that user only. No system privilege is required to set option for self. System privilege is required to set at database level or at user level for any user other than self.

Requires the SET ANY PUBLIC OPTION system privilege to set this option. Can be set temporary for an individual connection or for the PUBLIC role. Takes effect immediately.

Dependencies

FP_NBIT_LOOKUP_MB applies to databases running where FP_NBIT_IQ15_COMPATIBILITY='OFF'. If FP_NBIT_IQ15_COMPATIBILITY='ON', the database engine ignores this option.

Remarks

FP_NBIT_AUTOSIZE_LIMIT and FP_NBIT_LOOKUP_MB establish a ceiling for sizing implicit NBit columns. As long as the number of distinct values is less than FP_NBIT_AUTOSIZE_LIMIT and the total dictionary size (values and counts) is less the FP_NBIT_LOOKUP_MB, the column loads with an NBit FP index. Limits are enforced by the FP_NBIT_ENFORCE_LIMITS option.

DML operations that exceed the FP_NBIT_LOOKUP_MB limit rollover to a Flat FP index.

If an operation exceeds FP_NBIT_LOOKUP_MB and FP_NBIT_ROLLOVER_MAX_MB limits and FP_NBIT_ENFORCE_LIMITS='OFF', the NBit FP transitions to the next NBit level.

sp_iqindexmetadata returns details about Flat FP or NBit FP columns. sp_iqrebuildindex can change explicit or implicit NBit FP column limits, or reformat the default column index as Flat FP or NBit FP.

Additional Information

  • Reference: Building Blocks, Tables, and Procedures > System Procedures > Alphabetical List of System Stored Procedures > sp_iqrebuildindex
  • Reference: Building Blocks, Tables, and Procedures > System Procedures » Alphabetical List of System Stored Procedures > sp_iqindexmetadata
Related reference
FP_NBIT_AUTOSIZE_LIMIT Option
FP_NBIT_ENFORCE_LIMITS Option
FP_NBIT_IQ15_COMPATIBILITY Option
FP_NBIT_ROLLOVER_MAX_MB Option