| PostgreSQL | Full | Yes | pgvector KNN, FTS | docs |
| MySQL | Full | Yes | Table or catalog registration | docs |
| SQLite | Full | Yes | sqlite-vec KNN, FTS | docs |
| MongoDB | Full | No | Collections with point lookups | docs |
| Redis | Full | No | Hashes mapped to SQL rows | docs |
| DynamoDB | Full | Yes | Scan + filter pushdown | docs |
| SeekDB | Full | Yes | MySQL-wire CRUD, FULLTEXT, HNSW | docs |
| ClickHouse | Read | Yes | Columnar OLAP, filter/limit pushdown | docs |
| Lance | Read + job-write | No | KNN, BM25 FTS; job destination | docs |
| Apache Iceberg | Read | No | Schema evolution, partition pruning | docs |
| InfluxDB 3 | Read | No | Time series over Arrow Flight SQL | docs |
| S3 / GCS / Azure | Read | No | CSV, Parquet, Lance in object stores | docs |
| CSV / Parquet | Read | No | Local or remote files | docs |
| SaaS via Open Connector | Read | Yes | GitHub, Slack, Notion, Feishu, Gmail, Discord, Outlook, OneDrive, Google Drive, Dropbox packs as stable SQL tables; pushdown + TTL cache | docs |
| Documents | Read | No | PDF/Office/ODF/image → per-page Markdown, tables, images | docs |
| RSS / Atom | Read | Yes | Feeds as feeds + items; per-feed TTL cache, fault isolation, un-sandboxed fetch egress | docs |
| Graph (Apache AGE) | Read | Yes | Read-only openCypher over Postgres; YAML views as catalog tables, cypher_query UDTF | docs |