Fix pg Thread#kill during queries, cached plans after column type changes, timestamp instants

README.md

@@ -65,7 +65,7 @@ More: [the generated code for every driver](docs/Examples.md) (it is the plugin'
 | `overrides` | none | Change the type of columns / parameters, see [below](#overrides). |
 | `rename` | none | Rename tables (model class) and columns (attribute), e.g. `{authors: Writer, bio: biography}`; `schema.table` works too. |
 | `exactTableNames` | `false` | Keep table names as model names (`authors` → `Authors`) instead of singularizing them (`Author`). |
-| `preparedStatements` | `true` | `pg` only (an error with other drivers). `false` sends the SQL with every call instead of preparing it (needed behind pgbouncer in transaction mode). Statements dropped by `DEALLOCATE ALL` / `DISCARD ALL` are prepared again by their next call outside a transaction (inside one, that call raises and the transaction rolls back). Statements are named `Module::Class#method` (with a hash when longer than PostgreSQL's 63 bytes), so classes sharing a pool never run each other's SQL. |
+| `preparedStatements` | `true` | `pg` only (an error with other drivers). `false` sends the SQL with every call instead of preparing it (needed behind pgbouncer in transaction mode). Statements dropped by `DEALLOCATE ALL` / `DISCARD ALL`, and statements PostgreSQL refuses after a migration changed the type of a column they return (`PG::FeatureNotSupported`: cached plan must not change result type), are prepared again by their next call outside a transaction (inside one, that call raises and the transaction rolls back; the next call prepares the statement again). Statements are named `Module::Class#method` (with a hash when longer than PostgreSQL's 63 bytes), so classes sharing a pool never run each other's SQL. |
 
 Unknown or misspelled options are errors, with a hint for near misses (`generate_types` → `generateTypes`).
 Options shared by several `sql:` blocks can go in the top-level `options:` of `sqlc.yaml` under the plugin's name
@@ -125,6 +125,8 @@ end
   and rolls back when it raises or the thread is killed. An interrupt (`Timeout`, `Thread#raise`, `Thread#kill`) that
   arrives while `BEGIN`, `COMMIT` or `ROLLBACK` runs waits for it to finish, and a `BEGIN` / `COMMIT` that raises
   itself (a stopped `Async` task) is rolled back: the connection never goes back to the pool inside a transaction.
+  On PostgreSQL a query interrupted by any of them (inside or outside a transaction) is cancelled at once, so the
+  connection goes back to the pool idle and a killed transaction rolls back without waiting for its query.
   On MySQL a `Thread#kill` during a query closes that client (mysql2 cannot send `ROLLBACK` while it waits for the
   query's result), so the server rolls the transaction back and the pool replaces the client. On Ruby <3.3 with timeout <0.4, `break`, `return`, and
   `throw` also roll back because Timeout cannot be told apart; add `gem 'timeout', '>= 0.4'` to the generated Gemfile
@@ -195,6 +197,10 @@ server; duplicate keys and invalid values raise `Mysql2::Error` instead of being
   in the zone `mysql2` reads `DATETIME` / `TIMESTAMP` values back in, the process's local zone, or UTC for a client
   created with `database_timezone: :utc` (`connect(params.merge(database_timezone: :utc))`). The server also converts
   `TIMESTAMP` columns with the session `time_zone`, so keep that equal to the client's zone.
+* PostgreSQL: a `Time` parameter of a `timestamp` (without time zone) column (also in `:copyfrom` and batches) keeps
+  its instant whatever its UTC offset: it is written in the process's local zone, the zone the pg gem reads
+  `timestamp` values back in (PostgreSQL itself ignores the offset of a `timestamp` value). Elements of `timestamp[]`
+  arrays are written as given. `timestamptz` keeps the instant anyway.
 * A `String` passed to a PostgreSQL `json` / `jsonb` parameter is JSON text (`'{"a":1}'`): pass `'"hi"'` or
   `'hi'.to_json` for a JSON string. Hashes, Arrays, numbers, `true` / `false` and `nil` are encoded for you.
 * Enums are `String`s, with constants in `models.rb` (`ExtendedBioType::MEMOIR`, `ExtendedBioType::ALL`). Values that

docs/Coverage.md

@@ -17,7 +17,7 @@ only when the behavior is rejected or decided during generation and generated co
 | `sqlc.embed`, outer-join nil, same table embedded twice | [`test_embed`](../tests/end2end_pg.rb#test_embed), [`test_embed_on_the_outer_side_of_a_join_is_nil_without_a_match`](../tests/end2end_pg.rb#test_embed_on_the_outer_side_of_a_join_is_nil_without_a_match), [`test_same_table_embedded_twice`](../tests/end2end_pg.rb#test_same_table_embedded_twice) | [`test_embed`](../tests/end2end_mysql2.rb#test_embed), [`test_outer_join_embed_is_nil_without_a_match`](../tests/end2end_mysql2.rb#test_outer_join_embed_is_nil_without_a_match), [`test_same_table_embedded_twice`](../tests/end2end_mysql2.rb#test_same_table_embedded_twice) | [`test_embed`](../tests/end2end_sqlite3.rb#test_embed), [`test_outer_join_embed_is_nil_without_a_match`](../tests/end2end_sqlite3.rb#test_outer_join_embed_is_nil_without_a_match), [`test_same_table_embedded_twice`](../tests/end2end_sqlite3.rb#test_same_table_embedded_twice) | [`test_embedded_tables_become_model_attributes`](../test/features_test.rb#test_embedded_tables_become_model_attributes) |
 | Frozen Ruby 3.2+ `Data`, mutable older `Struct`, `with`, `to_h`, pattern matching | [`test_rows_and_embedded_models_have_supported_layout_and_pattern_matching`](../tests/end2end_pg.rb#test_rows_and_embedded_models_have_supported_layout_and_pattern_matching) | [`test_rows_and_embedded_models_have_supported_layout_and_pattern_matching`](../tests/end2end_mysql2.rb#test_rows_and_embedded_models_have_supported_layout_and_pattern_matching) | [`test_rows_and_embedded_models_have_supported_layout_and_pattern_matching`](../tests/end2end_sqlite3.rb#test_rows_and_embedded_models_have_supported_layout_and_pattern_matching) | [`test_struct_classes_are_valid_and_usable`](../test/features_test.rb#test_struct_classes_are_valid_and_usable), [`test_data_classes_are_usable`](../test/features_test.rb#test_data_classes_are_usable) |
 | Enums, constants (also for keyword / invalid names), database labels and MySQL `SET` | [`test_enum_column`](../tests/end2end_pg.rb#test_enum_column), [`test_enum_values_named_like_ruby_keywords_get_valid_constants`](../tests/end2end_pg.rb#test_enum_values_named_like_ruby_keywords_get_valid_constants) | [`test_enum_and_set_columns`](../tests/end2end_mysql2.rb#test_enum_and_set_columns), [`test_enum_values_named_like_ruby_keywords_get_valid_constants`](../tests/end2end_mysql2.rb#test_enum_values_named_like_ruby_keywords_get_valid_constants) | not supported by the SQLite schema | [`test_models_cover_tables_and_enums`](../test/features_test.rb#test_models_cover_tables_and_enums) |
-| PostgreSQL arrays, JSON/JSONB, type round trips and RBS | [`test_array_parameters`](../tests/end2end_pg.rb#test_array_parameters), [`test_remaining_postgresql_types_round_trip`](../tests/end2end_pg.rb#test_remaining_postgresql_types_round_trip), [`test_json_and_jsonb_parameters_round_trip_all_json_value_types`](../tests/end2end_pg.rb#test_json_and_jsonb_parameters_round_trip_all_json_value_types) | not PostgreSQL types | not PostgreSQL types | [`test_multi_dimensional_arrays`](../test/features_test.rb#test_multi_dimensional_arrays), [`test_more_postgres_types_composites_and_domains`](../test/features_test.rb#test_more_postgres_types_composites_and_domains) |
+| PostgreSQL arrays, JSON/JSONB, type round trips and RBS; a `Time` keeps its instant in a `timestamp` column whatever its offset | [`test_array_parameters`](../tests/end2end_pg.rb#test_array_parameters), [`test_remaining_postgresql_types_round_trip`](../tests/end2end_pg.rb#test_remaining_postgresql_types_round_trip), [`test_timestamp_parameters_keep_their_instant_whatever_their_offset`](../tests/end2end_pg.rb#test_timestamp_parameters_keep_their_instant_whatever_their_offset), [`test_json_and_jsonb_parameters_round_trip_all_json_value_types`](../tests/end2end_pg.rb#test_json_and_jsonb_parameters_round_trip_all_json_value_types) | not PostgreSQL types | not PostgreSQL types | [`test_multi_dimensional_arrays`](../test/features_test.rb#test_multi_dimensional_arrays), [`test_more_postgres_types_composites_and_domains`](../test/features_test.rb#test_more_postgres_types_composites_and_domains) |
 | MySQL unsigned integers, BIT, YEAR, DATETIME/TIME (a `Time` keeps its instant in any zone, also in `:copyfrom`), JSON, enums/SET and client quoting | not MySQL | [`test_client_side_quoting_round_trips_supported_values`](../tests/end2end_mysql2.rb#test_client_side_quoting_round_trips_supported_values), [`test_time_values_keep_their_instant_whatever_their_offset`](../tests/end2end_mysql2.rb#test_time_values_keep_their_instant_whatever_their_offset), [`test_time_values_follow_a_utc_database_timezone`](../tests/end2end_mysql2.rb#test_time_values_follow_a_utc_database_timezone), [`test_declared_types_match_runtime_values`](../tests/end2end_mysql2.rb#test_declared_types_match_runtime_values) | not MySQL | [`test_mysql_uses_client_side_binding_and_sqlite_closes_prepared_statements`](../test/features_test.rb#test_mysql_uses_client_side_binding_and_sqlite_closes_prepared_statements) |
 | SQLite affinity, JSON/UUID, and NUMERIC integer/float results | not SQLite | not SQLite | [`test_declared_types_match_runtime_values`](../tests/end2end_sqlite3.rb#test_declared_types_match_runtime_values), [`test_declared_types_with_parameters`](../tests/end2end_sqlite3.rb#test_declared_types_with_parameters) | [`test_sqlite_declared_types_follow_type_affinity`](../test/features_test.rb#test_sqlite_declared_types_follow_type_affinity), [`test_sqlite_json_and_uuid_declarations_are_strings`](../test/features_test.rb#test_sqlite_json_and_uuid_declarations_are_strings) |
 | SQLite `busy_handler_timeout=` waits for another connection without blocking other threads | not SQLite | not SQLite | [`test_busy_handler_timeout_waits_for_another_connection_without_blocking_threads`](../tests/end2end_sqlite3.rb#test_busy_handler_timeout_waits_for_another_connection_without_blocking_threads) | |
@@ -41,8 +41,8 @@ CI runs `test/coverage_map_test.rb`, which checks every linked test method exist
 | Transaction `tx` used from an `Enumerator`, `Fiber`, `Thread`, `Async` task and nested savepoint; `TransactionEnded` after the transaction | [`test_transaction_query_object_works_from_other_fibers_and_threads`](../tests/end2end_pg.rb#test_transaction_query_object_works_from_other_fibers_and_threads) | [`test_transaction_query_object_works_from_other_fibers_and_threads`](../tests/end2end_mysql2.rb#test_transaction_query_object_works_from_other_fibers_and_threads) | [`test_transaction_query_object_works_from_other_fibers_and_threads`](../tests/end2end_sqlite3.rb#test_transaction_query_object_works_from_other_fibers_and_threads) | |
 | PostgreSQL arrays of enums created after the connection was opened | [`test_enum_arrays_of_a_type_created_after_connecting_are_decoded`](../tests/end2end_pg.rb#test_enum_arrays_of_a_type_created_after_connecting_are_decoded) | not MySQL | not SQLite | |
 | Interrupts at `BEGIN` / `COMMIT` (`Thread#raise`, raised by the statement) roll back and leave no open transaction | [`test_interrupts_around_begin_and_commit_never_leave_the_connection_in_a_transaction`](../tests/end2end_pg.rb#test_interrupts_around_begin_and_commit_never_leave_the_connection_in_a_transaction) | [`test_interrupts_around_begin_and_commit_never_leave_the_connection_in_a_transaction`](../tests/end2end_mysql2.rb#test_interrupts_around_begin_and_commit_never_leave_the_connection_in_a_transaction) | [`test_interrupts_around_begin_and_commit_never_leave_the_database_in_a_transaction`](../tests/end2end_sqlite3.rb#test_interrupts_around_begin_and_commit_never_leave_the_database_in_a_transaction) | |
-| `Thread#kill` inside a transaction rolls back; on MySQL a kill during a query replaces the client and ends its transaction | [`test_thread_kill_rolls_back_and_leaves_connection_idle`](../tests/end2end_pg.rb#test_thread_kill_rolls_back_and_leaves_connection_idle) | [`test_thread_kill_rolls_back_and_leaves_connection_outside_transaction`](../tests/end2end_mysql2.rb#test_thread_kill_rolls_back_and_leaves_connection_outside_transaction), [`test_thread_kill_during_a_query_replaces_the_connection_and_ends_its_transaction`](../tests/end2end_mysql2.rb#test_thread_kill_during_a_query_replaces_the_connection_and_ends_its_transaction) | [`test_thread_kill_rolls_back_and_leaves_connection_inactive`](../tests/end2end_sqlite3.rb#test_thread_kill_rolls_back_and_leaves_connection_inactive) | |
-| PostgreSQL statements dropped by `DEALLOCATE ALL` / `DISCARD ALL` are prepared again | [`test_statements_are_prepared_again_after_deallocate_all`](../tests/end2end_pg.rb#test_statements_are_prepared_again_after_deallocate_all) | not MySQL (no server-side prepared statements) | not SQLite | [`test_statements_are_named_after_the_module_and_query_class`](../test/features_test.rb#test_statements_are_named_after_the_module_and_query_class) |
+| `Thread#kill` inside a transaction rolls back; on PostgreSQL a kill during a query (inside or outside a transaction) cancels it at once and leaves the connection idle; on MySQL a kill during a query replaces the client and ends its transaction | [`test_thread_kill_rolls_back_and_leaves_connection_idle`](../tests/end2end_pg.rb#test_thread_kill_rolls_back_and_leaves_connection_idle), [`test_thread_kill_during_a_query_cancels_it_and_leaves_the_connection_idle`](../tests/end2end_pg.rb#test_thread_kill_during_a_query_cancels_it_and_leaves_the_connection_idle) | [`test_thread_kill_rolls_back_and_leaves_connection_outside_transaction`](../tests/end2end_mysql2.rb#test_thread_kill_rolls_back_and_leaves_connection_outside_transaction), [`test_thread_kill_during_a_query_replaces_the_connection_and_ends_its_transaction`](../tests/end2end_mysql2.rb#test_thread_kill_during_a_query_replaces_the_connection_and_ends_its_transaction) | [`test_thread_kill_rolls_back_and_leaves_connection_inactive`](../tests/end2end_sqlite3.rb#test_thread_kill_rolls_back_and_leaves_connection_inactive) | |
+| PostgreSQL statements dropped by `DEALLOCATE ALL` / `DISCARD ALL`, or refused after a column type change (cached plan must not change result type), are prepared again | [`test_statements_are_prepared_again_after_deallocate_all`](../tests/end2end_pg.rb#test_statements_are_prepared_again_after_deallocate_all), [`test_statements_are_prepared_again_after_a_column_type_change`](../tests/end2end_pg.rb#test_statements_are_prepared_again_after_a_column_type_change) | not MySQL (no server-side prepared statements) | not SQLite | [`test_statements_are_named_after_the_module_and_query_class`](../test/features_test.rb#test_statements_are_named_after_the_module_and_query_class) |
 | `:execresult` with `RETURNING` runs the statement | covered by `:execresult` semantics | covered by `:execresult` semantics | [`test_execresult_with_returning_runs_the_statement`](../tests/end2end_sqlite3.rb#test_execresult_with_returning_runs_the_statement) | |
 | `:copyfrom` keeps the case of quoted / mixed-case table and column names (MySQL `LOAD DATA`) | [`test_copyfrom_keeps_the_case_of_table_and_column_names`](../tests/end2end_pg.rb#test_copyfrom_keeps_the_case_of_table_and_column_names) | [`test_copyfrom_keeps_the_case_of_table_and_column_names`](../tests/end2end_mysql2.rb#test_copyfrom_keeps_the_case_of_table_and_column_names) | [`test_copyfrom_keeps_the_case_of_table_and_column_names`](../tests/end2end_sqlite3.rb#test_copyfrom_keeps_the_case_of_table_and_column_names) | |
 | `:copyfrom` takes any `Enumerable` (empty, lazy, `Enumerator`) | [`test_copyfrom_takes_any_enumerable`](../tests/end2end_pg.rb#test_copyfrom_takes_any_enumerable) | [`test_copyfrom_takes_any_enumerable`](../tests/end2end_mysql2.rb#test_copyfrom_takes_any_enumerable) | [`test_copyfrom_takes_any_enumerable`](../tests/end2end_sqlite3.rb#test_copyfrom_takes_any_enumerable) | |

examples/pg/connection.rb

@@ -10,11 +10,19 @@ module ConnectionState
     def prepared_statements
       if @prepared_statements_pid != backend_pid
         @prepared_statements = ::Set[]
+        @stale_statements = ::Set[]
         @prepared_statements_pid = backend_pid
       end
       @prepared_statements
     end
 
+    # Statements whose result type changed under them (ALTER TABLE ... TYPE in a migration): deallocated before
+    # they are prepared again.
+    def stale_statements
+      prepared_statements
+      @stale_statements
+    end
+
     # Set inside #transaction: a lost connection is then not reconnected until the transaction block ends.
     attr_accessor :in_transaction
   end

examples/pg/connection.rbs

@@ -7,9 +7,12 @@ module PgCodegen
   module ConnectionState : _PgConnection
     @prepared_statements: ::Set[::String]
     @prepared_statements_pid: ::Integer
+    @stale_statements: ::Set[::String]
 
     def prepared_statements: () -> ::Set[::String]
 
+    def stale_statements: () -> ::Set[::String]
+
     attr_accessor in_transaction: bool?
   end