RE: [Patch] Optimize dropping of relation buffers using dlist

The patch looks almost good except for the minor ones:

(1)
+ for (i = 0; i < nnodes; i++)
+ {
+ RelFileNodeBackend rnode = smgr_reln[i]->smgr_rnode;
+
+ rnodes[i] = rnode;
+ }

You can write:

+ for (i = 0; i < nnodes; i++)
+ rnodes[i] = smgr_reln[i]->smgr_rnode;

(2)
+ if (!accurate || j >= MAX_FORKNUM ||

The correct condition would be:

+ if (j <= MAX_FORKNUM ||

because j becomes MAX_FORKNUM + 1 if accurate sizes for all forks could be obtained. If any fork's size is inaccurate, j is <= MAX_FORKNUM when exiting the loop, so you don't need to test for accurate flag.

(3)
+ {
+ goto buffer_full_scan;
+ return;
+ }

return after goto cannot be reached, so this should just be:

+ goto buffer_full_scan;

Regards
Takayuki Tsunakawa