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[PATCH 1/5] bootstrap: convert Typ to a List*
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* [PATCH 1/5] bootstrap: convert Typ to a List*
@ 2020-11-20 02:48  Justin Pryzby <[email protected]>
  0 siblings, 0 replies; 2+ messages in thread

From: Justin Pryzby @ 2020-11-20 02:48 UTC (permalink / raw)

---
 src/backend/bootstrap/bootstrap.c | 69 ++++++++++++++-----------------
 1 file changed, 31 insertions(+), 38 deletions(-)

diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index 6f615e6622..18eb62ca47 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -159,7 +159,7 @@ struct typmap
 	FormData_pg_type am_typ;
 };
 
-static struct typmap **Typ = NULL;
+static List *Typ = NIL; /* List of struct typmap* */
 static struct typmap *Ap = NULL;
 
 static Datum values[MAXATTR];	/* current row's attribute values */
@@ -597,7 +597,7 @@ boot_openrel(char *relname)
 	 * pg_type must be filled before any OPEN command is executed, hence we
 	 * can now populate the Typ array if we haven't yet.
 	 */
-	if (Typ == NULL)
+	if (Typ == NIL)
 		populate_typ_array();
 
 	if (boot_reldesc != NULL)
@@ -688,7 +688,7 @@ DefineAttr(char *name, char *type, int attnum, int nullness)
 
 	typeoid = gettype(type);
 
-	if (Typ != NULL)
+	if (Typ != NIL)
 	{
 		attrtypes[attnum]->atttypid = Ap->am_oid;
 		attrtypes[attnum]->attlen = Ap->am_typ.typlen;
@@ -877,36 +877,25 @@ populate_typ_array(void)
 	Relation	rel;
 	TableScanDesc scan;
 	HeapTuple	tup;
-	int			nalloc;
-	int			i;
-
-	Assert(Typ == NULL);
 
-	nalloc = 512;
-	Typ = (struct typmap **)
-		MemoryContextAlloc(TopMemoryContext, nalloc * sizeof(struct typmap *));
+	Assert(Typ == NIL);
 
 	rel = table_open(TypeRelationId, NoLock);
 	scan = table_beginscan_catalog(rel, 0, NULL);
-	i = 0;
 	while ((tup = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		Form_pg_type typForm = (Form_pg_type) GETSTRUCT(tup);
+		struct typmap *newtyp;
+		MemoryContext old;
 
-		/* make sure there will be room for a trailing NULL pointer */
-		if (i >= nalloc - 1)
-		{
-			nalloc *= 2;
-			Typ = (struct typmap **)
-				repalloc(Typ, nalloc * sizeof(struct typmap *));
-		}
-		Typ[i] = (struct typmap *)
-			MemoryContextAlloc(TopMemoryContext, sizeof(struct typmap));
-		Typ[i]->am_oid = typForm->oid;
-		memcpy(&(Typ[i]->am_typ), typForm, sizeof(Typ[i]->am_typ));
-		i++;
+		old = MemoryContextSwitchTo(TopMemoryContext);
+		newtyp = (struct typmap *) palloc(sizeof(struct typmap));
+		Typ = lappend(Typ, newtyp);
+		MemoryContextSwitchTo(old);
+
+		newtyp->am_oid = typForm->oid;
+		memcpy(&newtyp->am_typ, typForm, sizeof(newtyp->am_typ));
 	}
-	Typ[i] = NULL;				/* Fill trailing NULL pointer */
 	table_endscan(scan);
 	table_close(rel, NoLock);
 }
@@ -925,16 +914,17 @@ populate_typ_array(void)
 static Oid
 gettype(char *type)
 {
-	if (Typ != NULL)
+	if (Typ != NIL)
 	{
-		struct typmap **app;
+		ListCell *lc;
 
-		for (app = Typ; *app != NULL; app++)
+		foreach (lc, Typ)
 		{
-			if (strncmp(NameStr((*app)->am_typ.typname), type, NAMEDATALEN) == 0)
+			struct typmap *app = lfirst(lc);
+			if (strncmp(NameStr(app->am_typ.typname), type, NAMEDATALEN) == 0)
 			{
-				Ap = *app;
-				return (*app)->am_oid;
+				Ap = app;
+				return app->am_oid;
 			}
 		}
 	}
@@ -980,14 +970,17 @@ boot_get_type_io_data(Oid typid,
 	if (Typ != NULL)
 	{
 		/* We have the boot-time contents of pg_type, so use it */
-		struct typmap **app;
-		struct typmap *ap;
-
-		app = Typ;
-		while (*app && (*app)->am_oid != typid)
-			++app;
-		ap = *app;
-		if (ap == NULL)
+		struct typmap *ap = NULL;
+		ListCell *lc;
+
+		foreach (lc, Typ)
+		{
+			ap = lfirst(lc);
+			if (ap->am_oid == typid)
+				break;
+		}
+
+		if (!ap || ap->am_oid != typid)
 			elog(ERROR, "type OID %u not found in Typ list", typid);
 
 		*typlen = ap->am_typ.typlen;
-- 
2.26.2


--------------614DDB87AFFED893713AC0E9
Content-Type: text/x-patch; charset=UTF-8;
 name="0002-Allow-composite-types-in-bootstrap-20210304.patch"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
 filename="0002-Allow-composite-types-in-bootstrap-20210304.patch"



^ permalink  raw  reply  [nested|flat] 2+ messages in thread

* Re: pg_walcleaner - new tool to detect, archive and delete the unneeded wal files (was Re: pg_archivecleanup - add the ability to detect, archive and delete the unneeded wal files on the primary)
@ 2022-04-18 14:11  Stephen Frost <[email protected]>
  0 siblings, 0 replies; 2+ messages in thread

From: Stephen Frost @ 2022-04-18 14:11 UTC (permalink / raw)
  To: Bharath Rupireddy <[email protected]>; +Cc: PostgreSQL Hackers <[email protected]>; SATYANARAYANA NARLAPURAM <[email protected]>; Euler Taveira <[email protected]>

Greetings,

* Bharath Rupireddy ([email protected]) wrote:
> Thanks for the comments. Here's a new tool called pg_walcleaner which
> basically deletes (optionally archiving before deletion) the unneeded
> WAL files.
> 
> Please provide your thoughts and review the patches.

Alright, I spent some more time thinking about this and contemplating
what the next steps are... and I feel like the next step is basically
"add a HINT when the server can't start due to being out of disk space
that one should consider running pg_walcleaner" and at that point... why
aren't we just, uh, doing that?  This is all still quite hand-wavy, but
it sure would be nice to be able to avoid downtime due to a broken
archiving setup.  pgbackrest has a way of doing this and while we, of
course, discourage the use of that option, as it means throwing away
WAL, it's an option that users have.  PG could have a similar option.
Basically, to archive_command/library what max_slot_wal_keep_size is for
slots.

That isn't to say that we shouldn't also have a tool like this, but it
generally feels like we're taking a reactive approach here rather than a
proactive one to addressing the root issue.

Thanks,

Stephen


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^ permalink  raw  reply  [nested|flat] 2+ messages in thread


end of thread, other threads:[~2022-04-18 14:11 UTC | newest]

Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed)
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2020-11-20 02:48 [PATCH 1/5] bootstrap: convert Typ to a List* Justin Pryzby <[email protected]>
2022-04-18 14:11 Re: pg_walcleaner - new tool to detect, archive and delete the unneeded wal files (was Re: pg_archivecleanup - add the ability to detect, archive and delete the unneeded wal files on the primary) Stephen Frost <[email protected]>

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