recsplit: change default BucketSize (#13272)

Params:
- change default BucketSize: at `100` i don't see any size grow. but
build speed -30% and read speed -20%
- keep same default LeafSize: it increasing build speed, but decreasing
reads speed. so we do preoritize reads speed.

erigon-lib/kv/mdbx/kv_mdbx.go

@@ -1109,6 +1109,9 @@ func (tx *MdbxTx) stdCursor(bucket string) (kv.RwCursor, error) {
 	c := &MdbxCursor{bucketName: bucket, tx: tx, bucketCfg: b, id: tx.ID}
 	tx.ID++
 
+	if tx.tx == nil {
+		panic("assert: tx.tx nil. seems this `tx` was Rollback'ed")
+	}
 	var err error
 	c.c, err = tx.tx.OpenCursor(mdbx.DBI(tx.db.buckets[c.bucketName].DBI))
 	if err != nil {

erigon-lib/recsplit/recsplit.go

@@ -143,7 +143,7 @@ type RecSplitArgs struct {
 // DefaultLeafSize - LeafSize=8 and BucketSize=100, use abount 1.8 bits per key. Increasing the leaf and bucket
 // sizes gives more compact structures (1.56 bits per key), at the	price of a slower construction time
 const DefaultLeafSize = 8
-const DefaultBucketSize = 2000 // typical from 100 to 2000, with smaller buckets giving slightly larger but faster function
+const DefaultBucketSize = 100 // typical from 100 to 2000, with smaller buckets giving slightly larger but faster function
 
 // NewRecSplit creates a new RecSplit instance with given number of keys and given bucket size
 // Typical bucket size is 100 - 2000, larger bucket sizes result in smaller representations of hash functions, at a cost of slower access

erigon-lib/state/aggregator_test.go

@@ -547,13 +547,13 @@ func TestAggregatorV3_PruneSmallBatches(t *testing.T) {
 		require.NoError(t, err)
 		codeRangeAfter = extractKVErrIterator(t, it)
 
-		its, err := ac.d[kv.AccountsDomain].ht.HistoryRange(0, int(maxTx), order.Asc, maxInt, tx)
+		its, err := ac.d[kv.AccountsDomain].ht.HistoryRange(0, int(maxTx), order.Asc, maxInt, afterTx)
 		require.NoError(t, err)
 		accountHistRangeAfter = extractKVSErrIterator(t, its)
-		its, err = ac.d[kv.CodeDomain].ht.HistoryRange(0, int(maxTx), order.Asc, maxInt, tx)
+		its, err = ac.d[kv.CodeDomain].ht.HistoryRange(0, int(maxTx), order.Asc, maxInt, afterTx)
 		require.NoError(t, err)
 		codeHistRangeAfter = extractKVSErrIterator(t, its)
-		its, err = ac.d[kv.StorageDomain].ht.HistoryRange(0, int(maxTx), order.Asc, maxInt, tx)
+		its, err = ac.d[kv.StorageDomain].ht.HistoryRange(0, int(maxTx), order.Asc, maxInt, afterTx)
 		require.NoError(t, err)
 		storageHistRangeAfter = extractKVSErrIterator(t, its)
 	}