PostgreSQL clients (psql, pgx, DBeaver, Tableau, DataGrip,
pgAdmin) fire a barrage of catalog probes at connection time —
SELECT version(), SHOW server_version, SELECT FROM pg_namespace
/ pg_class / pg_type / pg_database / pg_settings. FiveSql2 can't
parse most of them. Without interception the BI tool either
errors out on connect or proceeds with a half-broken view of
the database (zero tables, no type info, no schema list). This
commit lands the minimum-viable catalog shim so the common
connect-and-list-tables flow succeeds.
Strategy
--------
Pattern-match catalog probes BEFORE handing the SQL to five_SQL.
Recognised shapes get synthesised result envelopes — same
`{ aFieldNames, aRows }` hbrt.Value shape the engine returns,
so the existing dispatchSimpleQuery / executePortal pipelines
stream them identically to a normal query.
Covered (v1.0)
--------------
* SET / RESET / DISCARD <name> → success, no-op
* SHOW <name> → single-row response
(server_version, server_encoding,
client_encoding, DateStyle,
transaction_isolation, etc.)
* SELECT version() / current_database() / current_schema() /
current_user / session_user / pg_backend_pid() → single-row
* SELECT … FROM pg_namespace → 2 rows (pg_catalog + public)
* SELECT … FROM pg_class → list of open workareas
(relkind='r', relnamespace=public)
* SELECT … FROM pg_attribute → empty (stub; column-shape
introspection deferred to v1.1)
* SELECT … FROM pg_type → 7 OIDs FiveSql2 actually emits
(bool, int4, int8, text, numeric,
date, timestamp)
* SELECT … FROM pg_database → 1 row, the connect-time db name
* SELECT … FROM pg_settings → name/setting pairs matching SHOW
* Anything else mentioning pg_catalog. / pg_<name> / information_schema.
→ empty result with generic field names (BI tool sees "0 rows" rather
than a parse error)
Deliberate non-goals
--------------------
* WHERE / JOIN evaluation — psql, pgx, DBeaver all filter
client-side on the rows we return. We send the whole
catalog and let them apply their predicates.
* pg_attribute introspection — would need to re-derive
column types from the open workarea + map back to PG OIDs.
Tracked as v1.1 work.
* Recursive CTE catalog queries (pgAdmin's tree builder uses
them) — too brittle to pattern-match. Falls through to
five_SQL where it errors loudly. pgAdmin's table-tree pane
will then show "0 tables" but the connection itself stays
alive.
Files
-----
hbrtl/pgserver/catalog.go (new, ~280 LOC)
catalogIntercept(sql) → (handled, value)
synthPgNamespace / synthPgClass / synthPgAttribute /
synthPgType / synthPgDatabase / synthPgSettings
simpleSelectFunction (version/current_*/pg_backend_pid)
showResponse (SHOW <name>)
hbrtl/pgserver/dispatch.go
dispatchSimpleQuery: catalogIntercept ahead of runSQL.
hbrtl/pgserver/extended.go
executePortal: same intercept, ahead of runSQL.
Verification
------------
psql against a running pgserver, with sslmode=require + MD5:
$ psql -c 'SELECT version()' -At
PostgreSQL 14.0 (FiveSql2) (FiveSql2 wire-compat shim)
$ psql -c 'SELECT * FROM pg_namespace' -At
11|pg_catalog|10
2200|public|10
$ psql -c 'SELECT * FROM pg_type' -At
16|bool|1
23|int4|4
20|int8|8
25|text|-1
1700|numeric|-1
1082|date|4
1114|timestamp|8
$ psql -l # \\l now works
데이터베이스 목록
oid | datname | datdba | 인코딩
-----+---------+--------+--------
1 | alice | 10 | 6
Integration script gates grew from 6/6 → 9/9:
PASS Catalog probe: SELECT version()
PASS Catalog probe: pg_namespace lists public + pg_catalog
PASS Catalog probe: SHOW server_version_num
All six release gates green:
go test ./... ✓
FiveSql2 SQL:1999 43/43 ✓
Harbour compat 56/56 ✓
std.ch 17/17 ✓
FRB 7/7 ✓
pgserver integration 9/9 ✓ (+3 from catalog stubs)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
CharlesKWON
ed1aeeb212