diff options
Diffstat (limited to 'src/backend/parser/analyze.c')
| -rw-r--r-- | src/backend/parser/analyze.c | 52 |
1 files changed, 45 insertions, 7 deletions
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c index 333be34fc46..ff1342e500a 100644 --- a/src/backend/parser/analyze.c +++ b/src/backend/parser/analyze.c @@ -296,6 +296,11 @@ transformStmt(ParseState *pstate, Node *parseTree) } #endif /* RAW_EXPRESSION_COVERAGE_TEST */ + /* + * Caution: when changing the set of statement types that have non-default + * processing here, see also stmt_requires_parse_analysis() and + * analyze_requires_snapshot(). + */ switch (nodeTag(parseTree)) { /* @@ -378,14 +383,22 @@ transformStmt(ParseState *pstate, Node *parseTree) } /* - * analyze_requires_snapshot - * Returns true if a snapshot must be set before doing parse analysis - * on the given raw parse tree. + * stmt_requires_parse_analysis + * Returns true if parse analysis will do anything non-trivial + * with the given raw parse tree. + * + * Generally, this should return true for any statement type for which + * transformStmt() does more than wrap a CMD_UTILITY Query around it. + * When it returns false, the caller can assume that there is no situation + * in which parse analysis of the raw statement could need to be re-done. * - * Classification here should match transformStmt(). + * Currently, since the rewriter and planner do nothing for CMD_UTILITY + * Queries, a false result means that the entire parse analysis/rewrite/plan + * pipeline will never need to be re-done. If that ever changes, callers + * will likely need adjustment. */ bool -analyze_requires_snapshot(RawStmt *parseTree) +stmt_requires_parse_analysis(RawStmt *parseTree) { bool result; @@ -398,6 +411,7 @@ analyze_requires_snapshot(RawStmt *parseTree) case T_DeleteStmt: case T_UpdateStmt: case T_SelectStmt: + case T_ReturnStmt: case T_PLAssignStmt: result = true; break; @@ -408,12 +422,12 @@ analyze_requires_snapshot(RawStmt *parseTree) case T_DeclareCursorStmt: case T_ExplainStmt: case T_CreateTableAsStmt: - /* yes, because we must analyze the contained statement */ + case T_CallStmt: result = true; break; default: - /* other utility statements don't have any real parse analysis */ + /* all other statements just get wrapped in a CMD_UTILITY Query */ result = false; break; } @@ -422,6 +436,30 @@ analyze_requires_snapshot(RawStmt *parseTree) } /* + * analyze_requires_snapshot + * Returns true if a snapshot must be set before doing parse analysis + * on the given raw parse tree. + */ +bool +analyze_requires_snapshot(RawStmt *parseTree) +{ + /* + * Currently, this should return true in exactly the same cases that + * stmt_requires_parse_analysis() does, so we just invoke that function + * rather than duplicating it. We keep the two entry points separate for + * clarity of callers, since from the callers' standpoint these are + * different conditions. + * + * While there may someday be a statement type for which transformStmt() + * does something nontrivial and yet no snapshot is needed for that + * processing, it seems likely that making such a choice would be fragile. + * If you want to install an exception, document the reasoning for it in a + * comment. + */ + return stmt_requires_parse_analysis(parseTree); +} + +/* * transformDeleteStmt - * transforms a Delete Statement */ |