Commit 4b01cb37 authored by Howard Chu's avatar Howard Chu
Browse files

ITS#8221 don't merge branch pages needlessly

parent ddb7478e
...@@ -7685,17 +7685,23 @@ mdb_rebalance(MDB_cursor *mc) ...@@ -7685,17 +7685,23 @@ mdb_rebalance(MDB_cursor *mc)
{ {
MDB_node *node; MDB_node *node;
int rc; int rc;
unsigned int ptop, minkeys; unsigned int ptop, minkeys, thresh;
MDB_cursor mn; MDB_cursor mn;
indx_t oldki; indx_t oldki;
minkeys = 1 + (IS_BRANCH(mc->mc_pg[mc->mc_top])); if (IS_BRANCH(mc->mc_pg[mc->mc_top])) {
minkeys = 1;
thresh = 1;
} else {
minkeys = 2;
thresh = FILL_THRESHOLD;
}
DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)", DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)",
IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch", IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]), mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]),
(float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10)); (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));
if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= FILL_THRESHOLD && if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= thresh &&
NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) { NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {
DPRINTF(("no need to rebalance page %"Z"u, above fill threshold", DPRINTF(("no need to rebalance page %"Z"u, above fill threshold",
mdb_dbg_pgno(mc->mc_pg[mc->mc_top]))); mdb_dbg_pgno(mc->mc_pg[mc->mc_top])));
...@@ -7829,8 +7835,7 @@ mdb_rebalance(MDB_cursor *mc) ...@@ -7829,8 +7835,7 @@ mdb_rebalance(MDB_cursor *mc)
* move one key from it. Otherwise we should try to merge them. * move one key from it. Otherwise we should try to merge them.
* (A branch page must never have less than 2 keys.) * (A branch page must never have less than 2 keys.)
*/ */
minkeys = 1 + (IS_BRANCH(mn.mc_pg[mn.mc_top])); if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= thresh && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
rc = mdb_node_move(&mn, mc); rc = mdb_node_move(&mn, mc);
if (mc->mc_ki[ptop]) { if (mc->mc_ki[ptop]) {
oldki++; oldki++;
......
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