temp index on addresses.tx_vin_vout_row_id for stake invalidation

db/dcrpg/indexing.go

@@ -556,7 +556,7 @@ func (pgb *ChainDB) IndexAll(barLoad chan *dbtypes.ProgressBarLoad) error {
 		// IndexAddressTable to create them all.
 		{Msg: "addresses table on tx hash", IndexFunc: IndexAddressTableOnTxHash},
 		{Msg: "addresses table on block time", IndexFunc: IndexBlockTimeOnTableAddress},
-		{Msg: "addresses table on address", IndexFunc: IndexAddressTableOnAddress},
+		{Msg: "addresses table on address", IndexFunc: IndexAddressTableOnAddress}, // TODO: remove or redefine this or IndexAddressTableOnVoutID since that includes address too
 		{Msg: "addresses table on vout DB ID", IndexFunc: IndexAddressTableOnVoutID},
 		//{Msg: "addresses table on matching tx hash", IndexFunc: IndexAddressTableOnMatchingTxHash},
 

db/dcrpg/internal/addrstmts.go

@@ -67,6 +67,8 @@ const (
 		` ON addresses(matching_tx_hash);`
 	DeindexAddressTableOnMatchingTxHash = `DROP INDEX IF EXISTS ` + IndexOfAddressTableOnMatchingTx + ` CASCADE;`
 
+	// TODO: figure out why this index exists since it's covered by the unique
+	// on tx_vin_vout_row_id too.
 	IndexAddressTableOnAddress = `CREATE INDEX IF NOT EXISTS ` + IndexOfAddressTableOnAddress +
 		` ON addresses(address);`
 	DeindexAddressTableOnAddress = `DROP INDEX IF EXISTS ` + IndexOfAddressTableOnAddress + ` CASCADE;`

db/dcrpg/internal/indexes.go

@@ -88,7 +88,7 @@ var IndexDescriptions = map[string]string{
 	IndexOfVinsTableOnPrevOut:              "vins on previous outpoint",
 	IndexOfVoutsTableOnTxHashInd:           "vouts on transaction hash and index",
 	IndexOfVoutsTableOnSpendTxID:           "vouts on spend_tx_row_id",
-	IndexOfAddressTableOnAddress:           "addresses table on address",
+	IndexOfAddressTableOnAddress:           "addresses table on address", // TODO: remove if it is redundant with IndexOfAddressTableOnVoutID
 	IndexOfAddressTableOnVoutID:            "addresses table on vout row id, address, and is_funding",
 	IndexOfAddressTableOnBlockTime:         "addresses table on block time",
 	IndexOfAddressTableOnTx:                "addresses table on transaction hash",

db/dcrpg/pgblockchain.go

@@ -3659,6 +3659,10 @@ func (pgb *ChainDB) UpdateLastBlock(msgBlock *wire.MsgBlock, isMainchain bool) e
 		}
 
 		// Update addresses table for last block's regular transactions.
+		// So slow without indexes:
+		//  Update on addresses  (cost=0.00..1012201.53 rows=1 width=181)
+		// 		->  Seq Scan on addresses  (cost=0.00..1012201.53 rows=1 width=181)
+		// 		Filter: ((NOT is_funding) AND (tx_vin_vout_row_id = 13241234))
 		err = UpdateLastAddressesValid(pgb.db, lastBlockHash.String(), lastIsValid)
 		if err != nil {
 			return fmt.Errorf("UpdateLastAddressesValid: %v", err)

db/dcrpg/sync.go

@@ -141,6 +141,16 @@ func (pgb *ChainDB) SyncChainDB(ctx context.Context, client rpcutils.MasterBlock
 			return lastBlock, err
 		}
 
+		// Create the temporary index on addresses(tx_vin_vout_row_id) that
+		// prevents the stake disapproval updates to a block to cause massive
+		// slowdown during initial sync without an index on tx_vin_vout_row_id.
+		log.Infof("Creating temporary index on addresses(tx_vin_vout_row_id).")
+		_, err = pgb.db.Exec(`CREATE INDEX IF NOT EXISTS idx_addresses_vinvout_id_tmp ` +
+			`ON addresses(tx_vin_vout_row_id)`)
+		if err != nil {
+			return lastBlock, err
+		}
+
 		// Disable duplicate checks on insert queries since the unique indexes
 		// that enforce the constraints will not exist.
 		pgb.EnableDuplicateCheckOnInsert(false)
@@ -377,6 +387,13 @@ func (pgb *ChainDB) SyncChainDB(ctx context.Context, client rpcutils.MasterBlock
 	// Index and analyze tables.
 	var analyzed bool
 	if reindexing {
+		// drop the temporary index on addresses(tx_vin_vout_row_id).
+		log.Infof("Dropping temporary index on addresses(tx_vin_vout_row_id).")
+		_, err = pgb.db.Exec(`DROP INDEX IF EXISTS idx_addresses_vinvout_id_tmp;`)
+		if err != nil {
+			return nodeHeight, err
+		}
+
 		// To build indexes, there must NOT be duplicate rows in terms of the
 		// constraints defined by the unique indexes. Duplicate transactions,
 		// vins, and vouts can end up in the tables when identical transactions
@@ -388,7 +405,8 @@ func (pgb *ChainDB) SyncChainDB(ctx context.Context, client rpcutils.MasterBlock
 			return 0, err
 		}
 
-		// Create all indexes except addresses and tickets indexes.
+		// Create all indexes except those on addresses.matching_tx_hash,
+		// vouts.spend_tx_row_id, and all tickets indexes.
 		if err = pgb.IndexAll(barLoad); err != nil {
 			return nodeHeight, fmt.Errorf("IndexAll failed: %v", err)
 		}