Documentation
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Overview ¶
Package postgres is a dfetch Connector backed by a PostgreSQL database over database/sql (jackc/pgx). It is a dynamic source: rather than declaring tables up front it lists/describes them on demand from information_schema, and it pushes a real SELECT (filters, ordering, LIMIT, and column projection) to the server. One connector maps one Postgres schema (default "public"); expose more schemas by registering more sources. It is config-only — there is no default DSN — so it is registered for `type: postgres` but never auto-instantiated.
Index ¶
- func New(params map[string]any) (source.Connector, error)
- type Connector
- func (c *Connector) DescribeTable(ctx context.Context, table string) (source.TableSchema, bool, error)
- func (c *Connector) ListTables(ctx context.Context, opts source.ListOptions) ([]string, error)
- func (c *Connector) Scan(ctx context.Context, req source.ScanRequest, emit func(*source.Rows) error) error
- func (c *Connector) Tables() []source.TableSchema
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func New ¶
New builds a Postgres connector. The DSN comes from params["dsn"], else $DFETCH_POSTGRES_DSN or $DATABASE_URL, else params "dsn_func"/"dsn_command" (see source.Credential); it is resolved — and the pool opened — on first use, so a missing DSN errors when a postgres table is queried, not at construction. Other params: "schema" (default "public") and "max_rows" (cap on an un-pushable-LIMIT scan; default 100000). It is config-only — registered for `type: postgres`, never auto-instantiated.
Types ¶
type Connector ¶
type Connector struct {
// contains filtered or unexported fields
}
Connector queries one schema of a PostgreSQL database.
func (*Connector) DescribeTable ¶
func (c *Connector) DescribeTable(ctx context.Context, table string) (source.TableSchema, bool, error)
DescribeTable resolves one table's columns from information_schema. found is false (nil error) when the table does not exist in the connector's schema.
func (*Connector) ListTables ¶
ListTables returns the base table and view names in the connector's schema, optionally filtered by a case-insensitive substring.
func (*Connector) Scan ¶
func (c *Connector) Scan(ctx context.Context, req source.ScanRequest, emit func(*source.Rows) error) error
Scan runs the pushed-down SELECT and emits rows in batches.
func (*Connector) Tables ¶
func (c *Connector) Tables() []source.TableSchema
Tables returns nil: tables are discovered on demand (ListTables/DescribeTable).
Source Files