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https://github.com/lancedb/lancedb.git
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feat: support IVF_RQ index type
Signed-off-by: BubbleCal <bubble-cal@outlook.com>
This commit is contained in:
@@ -804,6 +804,15 @@ describe("When creating an index", () => {
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});
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});
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it("should be able to create IVF_RQ", async () => {
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await tbl.createIndex("vec", {
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config: Index.ivfRq({
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numPartitions: 10,
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numBits: 1,
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}),
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});
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});
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it("should allow me to replace (or not) an existing index", async () => {
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await tbl.createIndex("id");
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// Default is replace=true
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@@ -85,6 +85,7 @@ export {
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Index,
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IndexOptions,
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IvfPqOptions,
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IvfRqOptions,
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IvfFlatOptions,
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HnswPqOptions,
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HnswSqOptions,
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@@ -112,6 +112,77 @@ export interface IvfPqOptions {
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sampleRate?: number;
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}
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export interface IvfRqOptions {
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/**
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* The number of IVF partitions to create.
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*
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* This value should generally scale with the number of rows in the dataset.
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* By default the number of partitions is the square root of the number of
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* rows.
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*
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* If this value is too large then the first part of the search (picking the
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* right partition) will be slow. If this value is too small then the second
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* part of the search (searching within a partition) will be slow.
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*/
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numPartitions?: number;
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/**
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* Number of bits per dimension for residual quantization.
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*
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* This value controls how much each residual component is compressed. The more
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* bits, the more accurate the index will be but the slower search. Typical values
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* are small integers; the default is 1 bit per dimension.
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*/
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numBits?: number;
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/**
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* Distance type to use to build the index.
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*
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* Default value is "l2".
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*
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* This is used when training the index to calculate the IVF partitions
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* (vectors are grouped in partitions with similar vectors according to this
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* distance type) and during quantization.
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*
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* The distance type used to train an index MUST match the distance type used
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* to search the index. Failure to do so will yield inaccurate results.
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*
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* The following distance types are available:
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*
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* "l2" - Euclidean distance.
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* "cosine" - Cosine distance.
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* "dot" - Dot product.
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*/
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distanceType?: "l2" | "cosine" | "dot";
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/**
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* Max iterations to train IVF kmeans.
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*
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* When training an IVF index we use kmeans to calculate the partitions. This parameter
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* controls how many iterations of kmeans to run.
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*
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* The default value is 50.
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*/
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maxIterations?: number;
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/**
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* The number of vectors, per partition, to sample when training IVF kmeans.
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*
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* When an IVF index is trained, we need to calculate partitions. These are groups
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* of vectors that are similar to each other. To do this we use an algorithm called kmeans.
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*
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* Running kmeans on a large dataset can be slow. To speed this up we run kmeans on a
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* random sample of the data. This parameter controls the size of the sample. The total
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* number of vectors used to train the index is `sample_rate * num_partitions`.
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*
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* Increasing this value might improve the quality of the index but in most cases the
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* default should be sufficient.
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*
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* The default value is 256.
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*/
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sampleRate?: number;
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}
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/**
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* Options to create an `HNSW_PQ` index
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*/
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@@ -523,6 +594,35 @@ export class Index {
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options?.distanceType,
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options?.numPartitions,
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options?.numSubVectors,
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options?.numBits,
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options?.maxIterations,
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options?.sampleRate,
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),
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);
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}
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/**
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* Create an IvfRq index
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*
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* IVF-RQ (RabitQ Quantization) compresses vectors using RabitQ quantization
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* and organizes them into IVF partitions.
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*
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* The compression scheme is called RabitQ quantization. Each dimension is quantized into a small number of bits.
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* The parameters `num_bits` and `num_partitions` control this process, providing a tradeoff
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* between index size (and thus search speed) and index accuracy.
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*
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* The partitioning process is called IVF and the `num_partitions` parameter controls how
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* many groups to create.
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*
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* Note that training an IVF RQ index on a large dataset is a slow operation and
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* currently is also a memory intensive operation.
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*/
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static ivfRq(options?: Partial<IvfRqOptions>) {
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return new Index(
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LanceDbIndex.ivfRq(
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options?.distanceType,
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options?.numPartitions,
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options?.numBits,
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options?.maxIterations,
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options?.sampleRate,
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),
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