Changelog

v0.5.0

Concurrent scans: EctoDBScanner.scan/1 no longer registers the repo under a fixed process name. Each scan starts its own anonymous repo instance (Ecto's dynamic-repo pattern), so multiple scans — against different databases or the same one — can run simultaneously from a single node without colliding on EctoDBScanner.Repo.
:schemas option on EctoDBScanner.scan/1. When present, only the listed schemas are scanned. The filter is applied at the query level in every catalog query (tables, columns, constraints, sizes, indexes, sequences) so excluded schemas cost nothing — in particular, heuristic enum detection never samples their data.
:exclude_schemas option on EctoDBScanner.scan/1. Schemas to skip in addition to the always-excluded system schemas (information_schema, pg_catalog, pg_toast). Applied at the query level like :schemas.
Table and column comments: PostgreSQL comments (COMMENT ON TABLE / COMMENT ON COLUMN, via obj_description / col_description) are now extracted for tables, views, and materialized views. New comment field (String.t() | nil) on %Result.Table{} and %Result.Column{}.

The EctoDBScanner.Scanner Reactor's repo input is now an %EctoDBScanner.RepoRef{} (repo module + instance pid) instead of a bare repo module, and every query step takes an options argument. Each step (and each spawned enum-sampling task) binds the dynamic repo to its own process via EctoDBScanner.RepoRef.bind/1 before querying. Callers invoking the Reactor directly can still pass a bare repo module — RepoRef.bind/1 passes it through unchanged.

One slow column no longer aborts the whole scan: heuristic enum detection's per-column Task.async_stream now uses on_timeout: :kill_task, so a column whose TABLESAMPLE sampling exceeds the timeout is dropped from the results instead of exiting the stream (which previously propagated out of the DetectEnums step and failed the entire Reactor.run). The default per-column timeout is also raised from 30 s to 60 s to match Postgrex's default.

:detect_enums option on EctoDBScanner.scan/1 (default true). Set to false to skip the cardinality-based heuristic entirely on databases where even sampled enum detection is too slow. PostgreSQL ENUM-typed columns continue to be detected via catalog lookup.
:enum_detection_timeout option on EctoDBScanner.scan/1 (default 60_000). Per-column sampling timeout in milliseconds for heuristic enum detection. Callers know more about their target DB's latency profile than the library does.
:enum_detection_max_concurrency option on EctoDBScanner.scan/1. Number of columns to sample in parallel. Defaults to pool_size - 1.

Avoid count(*) timeouts on large tables: QueryTables now derives per-table row counts from pg_class.reltuples (planner statistics) instead of running SELECT count(*) against every table. On databases with multi-million / billion-row tables this removes the most common scan-time timeout.
Sample large tables in heuristic enum detection: EnumDetector now uses TABLESAMPLE SYSTEM to bound the work of COUNT(DISTINCT col) and distinct-value collection on tables larger than 100k rows, so a single huge table can no longer drag the whole scan into a timeout. Tables below the threshold continue to scan in full.

:analyze option on EctoDBScanner.scan/1 (default true). Runs ANALYZE before scanning so the reltuples statistics used for row counts and sampling are fresh. Set analyze: false if statistics are already current or the connecting role lacks permission to analyze.

Database size: Report total database size in bytes via %Result.Database{size_bytes: ...}
Table sizes: Report table size, index size, and total size in bytes for each table
Row counts: Estimated row counts per table via PostgreSQL statistics (reltuples)
Index discovery: Discover non-primary-key indexes with name, type (btree, gin, etc.), uniqueness, and column list
Sequence discovery: Discover sequences with current value and owned_by column resolution
Check constraints: Discover check constraints with name and expression
Unique constraints: Discover unique constraints with name and column list

Connect to a PostgreSQL database at runtime and discover its full structure
Discover schemas, tables, views, and materialized views
Discover columns with type mapping from PostgreSQL types to generalized Elixir types
Detect primary key and foreign key constraints
Detect PostgreSQL ENUM types with their defined values
Heuristic detection of enum-like string columns based on cardinality analysis
Expose column default values and nullability
Parallel execution of independent scan steps via Reactor pipeline