landing_page/qdrant-landing/content/documentation/migrate-to-qdrant/from-pgvector.md

title, short_description, description, weight, partition

title	short_description	description	weight	partition
From pgvector	Move vector data out of pgvector tables into Qdrant for higher recall, advanced filtering, and horizontal scale.	Migrate from pgvector to Qdrant by streaming rows from Postgres tables into Qdrant collections for scalable vector search with payload filtering and sharding.	30	ecosystem

Migrate from pgvector to Qdrant

What You Need from Postgres

• Connection URL — a standard Postgres connection string
• Table name — the table containing your vector data

Concept Mapping

pgvector	Qdrant	Notes
Table	Collection	One-to-one mapping
Row	Point	Each row becomes a point
vector column	Vector	Mapped automatically
Other columns	Payload	All non-vector columns become payload fields
vector_cosine_ops	Cosine	pgvector returns distance (1 - similarity); Qdrant returns similarity
vector_l2_ops	Euclid	Direct mapping
vector_ip_ops	Dot	pgvector uses negative inner product for ordering; scores will be inverted

Run the Migration

docker run --net=host --rm -it registry.cloud.qdrant.io/library/qdrant-migration pg \
    --pg.url 'postgres://user:password@host:5432/dbname' \
    --pg.table 'your_embeddings_table' \
    --pg.key-column 'id' \
    --qdrant.url 'https://your-instance.cloud.qdrant.io:6334' \
    --qdrant.api-key 'your-qdrant-api-key' \
    --qdrant.collection 'your-collection'

Selecting Specific Columns

By default, all columns are migrated. Use --pg.columns to select specific ones:

docker run --net=host --rm -it registry.cloud.qdrant.io/library/qdrant-migration pg \
    --pg.url 'postgres://user:password@host:5432/dbname' \
    --pg.table 'your_embeddings_table' \
    --pg.key-column 'id' \
    --pg.columns 'id,embedding,title,category' \
    --qdrant.url 'https://your-instance.cloud.qdrant.io:6334' \
    --qdrant.api-key 'your-qdrant-api-key' \
    --qdrant.collection 'your-collection'

All pgvector-Specific Flags

Flag	Required	Description
--pg.url	Yes	Postgres connection string
--pg.table	Yes	Table name to migrate
--pg.key-column	Yes	Column to use as point ID
--pg.columns	No	Comma-separated columns to migrate (default: all)
--migration.num-workers	No	Parallel workers (default: number of CPU cores)

Qdrant-Side Options

Flag	Default	Description
--qdrant.distance-metric	cosine	Distance metric per vector field (map format)

Gotchas

• Partition structure: If you had manual partitions in pgvector (common at scale), verify that all partitions were migrated, not just the primary table.
• NULL handling: PostgreSQL NULLs may be dropped during export. Check that optional fields are represented correctly in Qdrant payloads.
• Index type and recall: pgvector supports IVFFlat and HNSW. If your baseline was captured with IVFFlat (lower recall), Qdrant's HNSW may return better results. This looks like a "mismatch" but is an improvement.
• Row count approximation: Postgres's n_live_tup is an estimate, not an exact count. Use SELECT COUNT(*) FROM your_table for accurate comparison during migration verification.

After Migration: Keeping Postgres and Qdrant in Sync

If you continue using Postgres as your source of truth alongside Qdrant, you'll need a sync strategy. The Data Synchronization Guide covers three approaches from simple dual-writes to production-grade Change Data Capture.

Next Steps

After migration, verify your data arrived correctly with the Migration Verification Guide.