Re: O(N^3) planning time in choose_plan_name() since 8c49a484e8e

On 28/10/2026 21:27, Manu wrote:
> So v2 keeps a counter per base name. Names are never released, so
> every smaller suffix is taken and the counter gives today's name. A
> suffixed name determines its base and suffix, split at the last
> underscore, so suffixed names can't collide with each other; only names
> used as given (CTE names, subquery aliases) can, and those are checked.
> No existing expected output changes, and a test-only build running the
> old algorithm alongside found no mismatch. check-world passes with
> cassert; REL_19_STABLE takes the patch as is.

One small suggestion: the suffix parsing in subplan_name_in_use() scans
the digits
multiple times across strspn, strlen, and strtoul. It might be a bit cleaner
to fold the validation and conversion together into a single pass.

Something like
-    if (suffix != NULL && suffix[1] >= '1' && suffix[1] <= '9' &&
-        strspn(suffix + 1, "0123456789") == strlen(suffix + 1) &&
-        strlen(suffix + 1) <= 10)
+    if (suffix != NULL && suffix[1] >= '1' && suffix[1] <= '9')
     {
-        char       *base = pnstrdup(name, suffix - name);
-        SubplanNameSuffix *entry = subplan_name_suffix(glob, base, false);
+        char       *endptr;
+        unsigned long val = strtoul(suffix + 1, &endptr, 10);

-        pfree(base);
-        if (entry != NULL && strtoul(suffix + 1, NULL, 10) <
entry->next_suffix)
-            return true;
+        if (*endptr == '\0')
+        {
+            char       *base = pnstrdup(name, suffix - name);
+            SubplanNameSuffix *entry = subplan_name_suffix(glob, base,
false);
+
+            pfree(base);
+            if (entry != NULL && val < entry->next_suffix)
+                return true;
+        }
     }

Not a big deal though...

Regards,
Ayoub