Postgres (`postgres`)¶

The postgres connector indexes table rows as searchable records. Each row becomes an object you can search by meaning, and each table also gets a schema summary so you can search the structure ("which table has an email column?") not just the data.

How MFS sees it¶

Tables live under their schema. Every table exposes its rows and its schema:

postgres://prod-db/
└── public/
    ├── tickets/
    │   ├── rows.jsonl     table_rows    → one searchable chunk per row
    │   └── schema.json    table_schema  → searchable column summary
    └── users/
        ├── rows.jsonl
        └── schema.json

Rows are chunked per-row. To make a table searchable you must tell the connector which columns carry text — see [[objects]] below. Without that, rows still enumerate and you can grep/cat them, but they produce no semantic chunks.

Credentials¶

You already have a database; what you need is a DSN and a read-only role.

postgresql://user:pass@host:5432/dbname

Cloud Postgres (RDS/Aurora, Cloud SQL, Azure): copy the connection string from the console; substitute the real password.
Self-hosted: run \conninfo in psql to read host/port/db/user.

A read-only role is enough — USAGE on each in-scope schema plus SELECT on its tables. Confirm connectivity from the machine that runs the server before handing the DSN to MFS:

psql "$DSN" -c "SELECT 1"
psql "$DSN" -c "\dt"

Configuration¶

dsn = "env:PG_DSN"
schemas = ["public"]
cursor_column = "updated_at"   # enables incremental re-sync
max_read_rows = 100000

[[objects]]
match = "/public/tickets"
text_fields = ["title", "description"]
locator_fields = ["id"]
metadata_fields = ["status", "updated_at"]

match targets the connector-relative object path (/public/tickets), which covers its rows.jsonl. text_fields become the embedded text; locator_fields let you reopen an exact row with cat --locator; metadata_fields are returned alongside hits for filtering and display.

Sync and freshness¶

When you set cursor_column (typically updated_at), the connector tracks the high-water mark and re-syncs only rows changed since the last run. Deletions are caught by full_scan. grep runs as a pushdown — it queries Postgres directly rather than the index.

Search and browse¶

mfs connector probe postgres://prod-db --config ./postgres.toml
mfs add postgres://prod-db --config ./postgres.toml

mfs search "SSO migration" postgres://prod-db/public/tickets/rows.jsonl
mfs search "email column" postgres://prod-db --kind schema_summary
mfs cat postgres://prod-db/public/tickets/rows.jsonl --locator '{"id":12345}'

Pitfalls¶

No text_fields → rows enumerate but produce no searchable chunks.
Use read-only credentials; the connector only needs SELECT.
max_read_rows caps large tables and can mark recall partial.

Postgres (postgres)¶