diff options
Diffstat (limited to 'src/backend/parser/analyze.c')
| -rw-r--r-- | src/backend/parser/analyze.c | 34 |
1 files changed, 11 insertions, 23 deletions
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c index a0e565b187c..efa4e47b1a4 100644 --- a/src/backend/parser/analyze.c +++ b/src/backend/parser/analyze.c @@ -17,7 +17,7 @@ * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.399 2010/01/02 16:57:48 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.400 2010/01/15 22:36:33 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -257,16 +257,12 @@ analyze_requires_snapshot(Node *parseTree) break; case T_ExplainStmt: - - /* - * We only need a snapshot in varparams case, but it doesn't seem - * worth complicating this function's API to distinguish that. - */ + /* yes, because we must analyze the contained statement */ result = true; break; default: - /* utility statements don't have any active parse analysis */ + /* other utility statements don't have any real parse analysis */ result = false; break; } @@ -1993,29 +1989,21 @@ transformDeclareCursorStmt(ParseState *pstate, DeclareCursorStmt *stmt) * transformExplainStmt - * transform an EXPLAIN Statement * - * EXPLAIN is just like other utility statements in that we emit it as a - * CMD_UTILITY Query node with no transformation of the raw parse tree. - * However, if p_coerce_param_hook is set, it could be that the client is - * expecting us to resolve parameter types in something like - * EXPLAIN SELECT * FROM tab WHERE col = $1 - * To deal with such cases, we run parse analysis and throw away the result; - * this is a bit grotty but not worth contorting the rest of the system for. - * (The approach we use for DECLARE CURSOR won't work because the statement - * being explained isn't necessarily a SELECT, and in particular might rewrite - * to multiple parsetrees.) + * EXPLAIN is like other utility statements in that we emit it as a + * CMD_UTILITY Query node; however, we must first transform the contained + * query. We used to postpone that until execution, but it's really necessary + * to do it during the normal parse analysis phase to ensure that side effects + * of parser hooks happen at the expected time. */ static Query * transformExplainStmt(ParseState *pstate, ExplainStmt *stmt) { Query *result; - if (pstate->p_coerce_param_hook != NULL) - { - /* Since parse analysis scribbles on its input, copy the tree first! */ - (void) transformStmt(pstate, copyObject(stmt->query)); - } + /* transform contained query */ + stmt->query = (Node *) transformStmt(pstate, stmt->query); - /* Now return the untransformed command as a utility Query */ + /* represent the command as a utility Query */ result = makeNode(Query); result->commandType = CMD_UTILITY; result->utilityStmt = (Node *) stmt; |