Inverted File Flat Index Syntax and Parameters

Review the syntax and examples for Inverted File Flat vector indexes.

Syntax

CREATE VECTOR INDEX <vector index name>
ON <table name> ( <vector column> )
[GLOBAL] ORGANIZATION [NEIGHBOR] PARTITIONS
[WITH] [DISTANCE <metric name>]
[WITH TARGET ACCURACY <percentage value>
[PARAMETERS ( TYPE IVF, { NEIGHBOR PARTITIONS <number of partitions> | 
                          SAMPLES_PER_PARTITION <number of samples> | 
                          MIN_VECTORS_PER_PARTITION <minimum number of vectors per partition> }
            )]]
[PARALLEL <degree of parallelism>]
[LOCAL];

The GLOBAL clause specifies a global IVF index. By default, IVF vector indexes are globally partitioned by centroid.

Specify the LOCAL clause to create a local IVF index.

IVF PARAMETERS

NEIGHBOR PARTITIONS determines the target number of centroid partitions that are created by the index.

SAMPLES_PER_PARTITION decides the total number of vectors that are passed to the clustering algorithm (samples_per_partition * neighbor_partitions). Passing all the vectors could significantly increase the total index creation time. The goal is to pass in a subset of vectors that can capture the data distribution.

MIN_VECTORS_PER_PARTITION represents the target minimum number of vectors per partition. The goal is to trim out any partition that can end up with few vectors (<= 100).

The valid range for IVF vector index parameters are:

• ACCURACY: > 0 and <= 100
• DISTANCE: EUCLIDEAN, L2_SQUARED (aka EUCLIDEAN_SQUARED), COSINE, DOT, MANHATTAN, HAMMING
• TYPE: IVF
• NEIGHBOR PARTITIONS: >0 and <= 10000000
• SAMPLES_PER_PARTITION: from 1 to (num_vectors/neighbor_partitions)
• MIN_VECTORS_PER_PARTITION: from 0 (no trimming of centroid partitions) to total number of vectors (would result in 1 centroid partition)

Examples

• To create a global IVF index:

  CREATE VECTOR INDEX galaxies_ivf_idx ON galaxies (embedding) 
  ORGANIZATION NEIGHBOR PARTITIONS
  DISTANCE COSINE
  WITH TARGET ACCURACY 95;

  CREATE VECTOR INDEX galaxies_ivf_idx ON galaxies (embedding) 
  ORGANIZATION NEIGHBOR PARTITIONS
  DISTANCE COSINE
  WITH TARGET ACCURACY 90 PARAMETERS (type IVF, neighbor partitions 10);

• To create a local IVF index:

  CREATE VECTOR INDEX galaxies_ivf_idx ON galaxies (embedding) 
  ORGANIZATION NEIGHBOR PARTITIONS
  DISTANCE COSINE
  WITH TARGET ACCURACY 90 PARAMETERS (type IVF, neighbor partitions 10)
  LOCAL;

For detailed information on the syntax, see CREATE VECTOR INDEX in Oracle Database SQL Language Reference.