Module triggers 

v7.12.4 — PL/pgSQL row-level trigger executor.

The catalogued spg_storage::FunctionDef carries the trigger function’s source body as raw text (between the original $$ ... $$). Each time a trigger fires we re-parse the body via spg_sql::parse_function_body and walk the resulting spg_sql::ast::PlPgSqlBlock against a NEW / OLD row context.

v7.12.4 surface (the minimum that lets a mailrs-shape update_search_vector trigger run end-to-end):

• NEW.col := <expr>; — mutate a NEW cell. BEFORE only.
• RETURN NEW; — pass the (possibly-mutated) row back to the row writer.
• RETURN OLD; — return the pre-change row.
• RETURN NULL; / RETURN; — skip the write (BEFORE) or no-op the notification (AFTER).
• sub-expression eval recurses through the regular crate::eval::eval_expr so anything the SELECT executor can compute is fair game inside a trigger body.

Out of scope for v7.12.4 (land in v7.12.5+):

• DECLARE’d local variables
• IF / ELSIF / ELSE / END IF; control flow
• Embedded SQL statements (UPDATE … WHERE …, SELECT … INTO var)
• RAISE NOTICE / RAISE EXCEPTION
• Loop constructs

Structs

DeferredEmbeddedStmt

v7.12.7 — embedded SQL statement collected during a trigger fire, queued for execution after the firing DML completes. NEW / OLD / DECLARE-local references inside the statement’s Expr tree have already been substituted with literals; the engine just feeds it to execute_stmt_with_cancel.

TgMeta

v7.39 (read01 round 82) — the firing trigger’s identity, for the TG_* magic variables. op is INSERT / UPDATE / DELETE; level is ROW (SPG fires row-level triggers only). TG_WHEN derives from is_after.

Enums

TriggerError

Result type the trigger executor exposes. Wraps EvalError at the eval-of-expressions layer and adds trigger-specific failure modes (OLD.col := …, unsupported PL/pgSQL feature, body that fails to re-parse, …).

TriggerOutcome

What the trigger function returned. Drives the row-write path the trigger fired from.

Functions

call_plpgsql_scalar

v7.39 (read01 round 64) — run a plpgsql body as a SCALAR function: the same interpreter the DO block and the triggers use, with no NEW / OLD, the arguments pre-bound as locals, and RETURN <expr> actually EVALUATED (the trigger path discards it — resolve_return’s own comment said “the scalar UDF surface in a later release handles RETURN properly”).

execute_do_block_top_level

v7.16.2 — execute a DO block’s PlPgSqlBlock at top level. Different from fire_row_trigger in three ways:

fire_row_trigger

Fire a single row-level trigger.

matching_trigger_names

v7.12.4 — find the triggers that should fire for a given (table, event, timing) tuple. Returns names so the caller can iterate without holding a borrow on the catalog while it mutates rows.

Type Aliases

ForQueryResolver

v7.37.20 (20.5) — callback shape the DO-block executor registers on BodyCtx for FOR-IN-SELECT loops. Runs the supplied SELECT statement against the engine and returns every row’s values. v7.39 (read01 round 64) — the COLUMN NAMES ride along now, so the loop can bind a record variable’s fields (rec.v), not just its first cell.

NoticeSink

v7.39 (round 757, F31-B3) — where RAISE NOTICE / WARNING / INFO deliver their rendered messages. The caller drains it into the session’s pending notices, and pgwire ships one NoticeResponse per entry; None (the SELECT-path scalar-function caller, which holds the engine immutably) drops them — ledgered as the B3 residual.

SelectIntoResolver

v7.16.2 — callback shape the DO-block executor registers on BodyCtx. Runs the supplied SELECT statement against the engine, returns the first row’s first column.