database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-30 21:42:05 +03:00
Code Activity

Adjust things so that the query_string of a cached plan and the sourceText of

Browse Source 
a portal are never NULL, but reliably provide the source text of the query.
It turns out that there was only one place that was really taking a short-cut,
which was the 'EXECUTE' utility statement.  That doesn't seem like a
sufficiently critical performance hotspot to justify not offering a guarantee
of validity of the portal source text.  Fix it to copy the source text over
from the cached plan.  Add Asserts in the places that set up cached plans and
portals to reject null source strings, and simplify a bunch of places that
formerly needed to guard against nulls.

There may be a few places that cons up statements for execution without
having any source text at all; I found one such in ConvertTriggerToFK().
It seems sufficient to inject a phony source string in such a case,
for instance
        ProcessUtility((Node *) atstmt,
                       "(generated ALTER TABLE ADD FOREIGN KEY command)",
                       NULL, false, None_Receiver, NULL);

We should take a second look at the usage of debug_query_string,
particularly the recently added current_query() SQL function.

ITAGAKI Takahiro and Tom Lane
This commit is contained in:
Tom Lane
2008-07-18 20:26:06 +00:00
parent 6cc88f0af5
commit a1c692358b
11 changed files with 66 additions and 65 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
src/backend/utils/cache/plancache.c vendored
View File

@ -33,7 +33,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/cache/plancache.c,v 1.18 2008/05/12 20:02:02 alvherre Exp $
* $PostgreSQL: pgsql/src/backend/utils/cache/plancache.c,v 1.19 2008/07/18 20:26:06 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -104,8 +104,7 @@ InitPlanCache(void)
* about all that we do here is copy it into permanent storage.
*
* raw_parse_tree: output of raw_parser()
* query_string: original query text (can be NULL if not available, but
* that is discouraged because it degrades error message quality)
* query_string: original query text (as of PG 8.4, must not be NULL)
* commandTag: compile-time-constant tag for query, or NULL if empty query
* param_types: array of parameter type OIDs, or NULL if none
* num_params: number of parameters
@ -130,6 +129,8 @@ CreateCachedPlan(Node *raw_parse_tree,
MemoryContext source_context;
MemoryContext oldcxt;
Assert(query_string != NULL); /* required as of 8.4 */
/*
* Make a dedicated memory context for the CachedPlanSource and its
* subsidiary data. We expect it can be pretty small.
@ -152,7 +153,7 @@ CreateCachedPlan(Node *raw_parse_tree,
oldcxt = MemoryContextSwitchTo(source_context);
plansource = (CachedPlanSource *) palloc(sizeof(CachedPlanSource));
plansource->raw_parse_tree = copyObject(raw_parse_tree);
plansource->query_string = query_string ? pstrdup(query_string) : NULL;
plansource->query_string = pstrdup(query_string);
plansource->commandTag = commandTag; /* no copying needed */
if (num_params > 0)
{
@ -228,6 +229,8 @@ FastCreateCachedPlan(Node *raw_parse_tree,
OverrideSearchPath *search_path;
MemoryContext oldcxt;
Assert(query_string != NULL); /* required as of 8.4 */
/*
* Fetch current search_path into given context, but do any recalculation
* work required in caller's context.