Files

123 lines
5.0 KiB
Python

"""Persist dimension-checked vector snapshots with composite scope constraints."""
import sqlalchemy as sa
from alembic import op
revision = "0006_vectors"
down_revision = "0005_chunk_indexes"
branch_labels = None
depends_on = None
class ExtensionVector(sa.types.UserDefinedType):
"""Qualify extension type without adding public business tables to search_path."""
def get_col_spec(self, **kw):
return "public.vector"
def upgrade():
schema = op.get_bind().scalar(
sa.text("SELECT extnamespace::regnamespace::text FROM pg_extension WHERE extname='vector'")
)
if schema != "public":
raise RuntimeError("vector 扩展须安装在 public;请由数据库管理员核对,迁移不会移动共享扩展")
op.create_unique_constraint("uq_chunk_text_scope", "chunks", ["id", "index_version_id"])
op.create_table(
"embedding_spaces",
sa.Column("id", sa.String(64), primary_key=True),
sa.Column("dimension", sa.Integer(), nullable=False),
sa.Column("spec", sa.JSON(), nullable=False),
sa.UniqueConstraint("id", "dimension", name="uq_embedding_space_dimension"),
sa.CheckConstraint("dimension BETWEEN 1 AND 2000", name="ck_embedding_space_dimension"),
)
op.create_table(
"vector_versions",
sa.Column("id", sa.String(36), primary_key=True),
sa.Column(
"text_index_version_id",
sa.String(36),
sa.ForeignKey("index_versions.id"),
nullable=False,
),
sa.Column("space_id", sa.String(64), nullable=False),
sa.Column("dimension", sa.Integer(), nullable=False),
sa.Column("chunk_count", sa.Integer(), nullable=False),
sa.Column("status", sa.String(20), nullable=False),
sa.Column("created_by", sa.Integer(), sa.ForeignKey("users.id"), nullable=False),
sa.Column(
"created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False
),
sa.Column("published_at", sa.DateTime(timezone=True)),
sa.ForeignKeyConstraint(
["space_id", "dimension"],
["embedding_spaces.id", "embedding_spaces.dimension"],
name="fk_vector_version_space",
),
sa.UniqueConstraint(
"id", "text_index_version_id", "space_id", "dimension", name="uq_vector_version_scope"
),
sa.CheckConstraint(
"status IN ('ready', 'published', 'superseded')", name="ck_vector_version_status"
),
sa.CheckConstraint("chunk_count BETWEEN 0 AND 2000", name="ck_vector_version_count"),
)
op.create_table(
"chunk_vectors",
sa.Column("version_id", sa.String(36), primary_key=True),
sa.Column("chunk_id", sa.String(36), primary_key=True),
sa.Column("text_index_version_id", sa.String(36), nullable=False),
sa.Column("space_id", sa.String(64), nullable=False),
sa.Column("dimension", sa.Integer(), nullable=False),
sa.Column("embedding", ExtensionVector(), nullable=False),
sa.ForeignKeyConstraint(
["version_id", "text_index_version_id", "space_id", "dimension"],
[
"vector_versions.id",
"vector_versions.text_index_version_id",
"vector_versions.space_id",
"vector_versions.dimension",
],
name="fk_chunk_vector_scope",
),
sa.ForeignKeyConstraint(
["chunk_id", "text_index_version_id"],
["chunks.id", "chunks.index_version_id"],
name="fk_chunk_vector_text",
),
sa.CheckConstraint("public.vector_dims(embedding) = dimension", name="ck_vector_dimension"),
sa.CheckConstraint(
"public.vector_norm(embedding) BETWEEN 0.9999 AND 1.0001", name="ck_vector_unit_norm"
),
)
op.create_table(
"vector_state",
sa.Column("id", sa.Integer(), primary_key=True),
sa.Column("active_version_id", sa.String(36), sa.ForeignKey("vector_versions.id")),
sa.Column("generation", sa.Integer(), nullable=False),
sa.CheckConstraint("id = 1", name="ck_vector_state_singleton"),
)
op.execute(sa.text("INSERT INTO vector_state (id, generation) VALUES (1, 0)"))
op.create_table(
"vector_publications",
sa.Column("generation", sa.Integer(), primary_key=True),
sa.Column("previous_version_id", sa.String(36), sa.ForeignKey("vector_versions.id")),
sa.Column("version_id", sa.String(36), sa.ForeignKey("vector_versions.id"), nullable=False),
sa.Column("actor_id", sa.Integer(), sa.ForeignKey("users.id"), nullable=False),
sa.Column(
"published_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False
),
)
def downgrade():
for table in [
"vector_publications",
"vector_state",
"chunk_vectors",
"vector_versions",
"embedding_spaces",
]:
op.drop_table(table)
op.drop_constraint("uq_chunk_text_scope", "chunks", type_="unique")