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Empties a collection and marks it as not existing.

public Task EnsureCollectionDeletedAsync(string name, CancellationToken cancellationToken = default)

Parameters — name is the collection to delete. cancellationToken is accepted for the abstraction's sake and not observed.

Returns — a completed Task.

Example — the records go, the collection object stays usable.

using Lodestar.Extensions.VectorData;
using Microsoft.Extensions.VectorData;

static async Task<string> DeleteAsync()
{
    using var store = new LodestarVectorStore();
    VectorStoreCollection<string, Note> notes = store.GetCollection<string, Note>("notes");
    await notes.UpsertAsync(new Note { Id = "a", Text = "a note", Embedding = new float[] { 1f, 0f, 0f } });

    await store.EnsureCollectionDeletedAsync("notes");
    bool gone = await notes.GetAsync("a") is null;
    bool exists = await store.CollectionExistsAsync("notes");

    return $"{gone} {exists}";
}

string after = DeleteAsync().GetAwaiter().GetResult();  // => True False

Remarks — "ensure" means it cannot fail for being already done. A name the store has never handed out, or a collection deleted twice, completes without error — which is the abstraction's contract, and what lets a caller delete at the start of a run without checking first.

The store keeps the collection object. LodestarVectorStore.GetCollection with the same name returns the same, now empty, instance, and a write to it makes it exist again. Forgetting it would let a second request build a second collection under a name a caller may still hold the first one for. The name is not reserved for the old schema, though: a request under a different TKey or TRecord, before anything writes to the deleted collection, replaces it with a new one, and the store then answers for the new one alone.

Applies to — net10.0, netstandard2.0.

See also — LodestarVectorStoreCollection.EnsureCollectionDeletedAsync, LodestarVectorStore.